Melbourne School of Psychological Sciences - Theses
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ItemThe hyper-ordinary depression hypothesis, and mechanisms of cognitive rigidity in depression (or zen and art of reducing depressive cycle maintenance)( 2017)This thesis is comprised of two related parts: a theoretical inquiry into the antidepressant mechanisms of a range of Non-ordinary States of Consciousness (NSCs), alongside the development of a novel mechanistic account of depression; and a set of four empirical studies that investigated aspects of cognitive rigidity in depression that relate to this novel account. In Chapter 1, I show that various disparate induction procedures (e.g., mindfulness practice, psychedelics, brain entrainment, and endurance exercise) are associated with both the production of NSCs and the reduction of depressive symptoms. Interestingly, these NSCs have in common many core neurological, psychological, and phenomenological features that are antithetical to core features of depression. I suggest that these features of NSCs represent potential therapeutic mechanisms, and that the production of certain NSCs mediates the reduction in depressive symptoms. I argue that two related superordinate features underlie these changes – enhanced Receptivity (e.g., perceptual, particular, absorbed, suggestible, flexible, open) and enhanced Projectivity (e.g., self-efficacious, intimate, relational, self-transcendent), that together represent elevated Interdependence between the individual and the world. In contrast, I argue that numerous features of depression appear to represent a fundamental deficiency in Interdependent processing, and that this deficiency extends into the most basic level of minimal subjectivity, representing a global qualitative change that satisfies criteria for an altered state of consciousness. Consequently, I argue that depression is associated with a ‘Hyper-ordinary’ state of consciousness. I suggest that the degree to which an NSC can reduce depression is a function of the degree to which Interdependent processing occurs within the state, and endures thereafter. Chapters 2, 3, and 4 report on a set of four empirical studies that investigated cognitive abnormalities in depression associated with the Receptivity aspect of the Hyper-ordinary account of depression. These tasks explored the link between depressive symptoms and three related processes that fall under the rubric of ‘cognitive flexibility’ – the ability for unexpected information to gain access to awareness; the ability to generate divergent representations for that information; and the ability to abandon extant representations in favour of those that are more compatible with unexpected information. As depression is associated with various forms of cognitive rigidity, including biased beliefs and interpretations that resist change, these studies investigated processing abnormalities in depression that might account for such rigidities. Additionally, as cognitive rigidity in depression is typically confined to specific forms of information processing, the tasks all employed stimuli that are highly relevant to the level of construal, the thematic content, and the rhetorical mode of depressotypic thinking, thereby increasing their sensitivity to detect differences, and their ability to reveal potential therapeutic targets. Results showed that depressive symptoms were related to slower access to awareness for unexpected positive information (Chapter 4), deficits in producing diverse categories of response, with no relation to the total number of responses generated (Chapter 3), and deficits in updating interpretations, regardless of whether updating resulted in a more positive or negative interpretation (Chapter 2). Together, this thesis offers a novel account of the depression experience, argues for a set of plausible therapeutic candidates for the antidepressant effects of certain NSCs, and reports on three novel tasks that probe ecologically relevant features of cognitive rigidity in depression, thereby revealing novel therapeutic targets. The picture of depression that emerges from the theoretical account is of a profoundly isolated state characterised by a fundamental deficit in the individual’s susceptibility to be affected by their context, and the perception that one’s context cannot be affected by the individual. The empirical studies show how this deficiency relates to the diminished influence of contextual factors over interpretations and expectations in depression. The hope is that this work can improve and extend the current understanding of depression and its causes, and lead to new methods of recovery.
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ItemPsychological outcomes of those experiencing early pregnancy loss( 2019)Early Pregnancy Loss (EPL), a loss occurring before 14 weeks gestation, is a relatively common event, occurring in about 20% of pregnancies. Although many women and their partners do not experience psychological difficulties associated with this loss, a significant minority experience intense and sustained grief, depression and anxiety symptoms. Reliable prevalence rates of serious psychological consequences for women are not well established, and those of partners are largely unknown. Furthermore, it is unclear what factors increase the risk for developing serious psychological symptoms. A range of potential risk factors have been identified, but remain under-researched and have not been rigorously studied. According to Cognitive Behavioural Theory, it is possible that cognitions surrounding the loss may be a particularly relevant risk factor. Yet this topic has rarely been examined and the studies that have are characterised by major methodological shortcomings. Importantly, partners are rarely included in these studies. This study aimed to determine prevalence rates for grief depression and anxiety over the first three and a half months after EPL. It also investigated cognitions after EPL through the Common-Sense Model of Illness Representation, and their link with grief, depression and anxiety symptoms. This study included 28 male partners and 68 women diagnosed with EPL who attended the Early Pregnancy Assessment Service at the Royal Women’s Hospital in Melbourne, Australia. Participants completed self-report measures two weeks (T1), and three months (T2) post-loss. These included the Perinatal Grief Scale, the Centre for Epidemiological Studies-Depression scale, the State Trait Anxiety Inventory, and the Illness Perception Questionnaire-Revised. Results showed that the prevalence of grief, depression and anxiety symptoms for women at T1 were 20.6%, 54.4%, and 52.9%, respectively. For partners, the prevalence rates were 0% for grief, 32.1% for depression, and 25% for anxiety. These rates decreased by T2. Illness perceptions were found to significantly predict grief, depression and anxiety. Unexpectedly, it was often better perceptions of the loss that predicted worse psychological outcomes. These findings provide new information about the experience of EPL and suggest that critical timing for assessment and treatment would be within the first 3 months after EPL. Treatment options, particularly in terms of grief theories presented in the introduction, are discussed. Considering the surprising results and that this is the first study to examine illness perceptions among this sample, replication of these results is needed.
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ItemThe SENSE Study (Sleep and Education: learning New Skills Early): long-term outcomes of a randomised controlled trial of a cognitive-behavioural and mindfulness-based group sleep intervention to prevent depression and improve anxiety in at-risk adolescents( 2019)Objective: Depression is one of the most common and debilitating mental health problems and its incidence dramatically increases during adolescence. Accumulating evidence suggests that adolescent depression can be prevented with psychosocial interventions, but there is still insufficient evidence to support their widespread implementation. Notably, there is a need for randomised controlled trials of novel interventions that are delivered to community-based adolescents identified to be at-risk for developing depression (i.e., targeted prevention) rather than the general adolescent population (i.e., universal prevention). Improving sleep represents a promising and innovative therapeutic target for the prevention of adolescent depression. Not only are sleep problems, including insufficient and poor-quality sleep, common during adolescence, they also tend to precipitate the onset of depression. Further, sleep interventions may be especially effective if they are delivered to adolescents experiencing anxiety. Anxiety, particularly generalised anxiety, and sleep problems often co-occur, and anxiety is also a risk factor for the development of depression. Evidence from a small but growing number of studies indicates that multicomponent cognitive-behavioural and mindfulness-based sleep interventions can improve sleep in adolescent samples. However, few studies have investigated depression and anxiety outcomes, particularly using randomised controlled designs, active control comparison conditions, extended follow-up periods, a multi-method assessment of sleep (i.e., subjective and objective measures) and mental health (i.e., diagnosis and symptoms) outcomes, and in community-based samples. Notably, no randomised controlled trial has investigated whether a sleep intervention can prevent the first onset of major depressive disorder (MDD) in adolescents. The current study was designed to address these gaps in the literature. The primary aim of the study was to investigate the long-term efficacy of a seven-week cognitive-behavioural and mindfulness-based group sleep intervention for the targeted prevention of first onset MDD and improvement of depressive symptoms over a two-year follow-up period in community-based adolescents experiencing concurrent high levels of anxiety symptoms and sleep problems (i.e., ‘at-risk’ for depression). Given the association between sleep and anxiety, notably generalised anxiety disorder (GAD), and dearth of adolescent sleep intervention studies investigating anxiety outcomes, the secondary and exploratory aim of the study was to investigate the long-term efficacy of the sleep intervention for preventing the incidence of GAD and improving anxiety symptoms over a two-year follow-up period. Importantly, the study aimed to demonstrate that any beneficial effects to depression and/or anxiety outcomes occurred via the putative mechanism of improvements to subjective and objective indices of sleep. As best can be determined, the research reported in this thesis represents the only attempt to date to prevent first onset MDD by improving sleep in an adolescent sample, and the only randomised controlled trial of an adolescent sleep intervention to examine anxiety outcomes over a two-year follow-up period. It was predicted that, compared to adolescents allocated to the active control (study skills) intervention, adolescents allocated to the sleep treatment intervention would: show greater improvements in subjective and objective indices of sleep (i.e., reduced sleep onset latency, increased total sleep time, better overall sleep quality, and reduced weekday bedtime intra-individual variability and weekday-to-weekend bedtime shift) immediately following the intervention and over the two-year follow-up period; be less likely to develop first onset MDD during, and would report lower levels of depressive symptoms at, the two-year follow-up (primary outcomes); and would be less likely to develop new onset GAD during, and would report lower levels of anxiety symptoms at, the two-year follow-up (secondary outcomes). Further, it was predicted that any beneficial long-term effects for depression and anxiety outcomes (i.e., lower incidence of MDD or GAD and/or reduction in depressive and anxiety symptoms) would be significantly mediated by improvements in sleep associated with the sleep treatment intervention (i.e., sleep improvements immediately post-intervention and/or over the two-year follow-up period). Methods: Participant recruitment and eligibility assessments occurred from January 2013 to June 2014. A school-based screening (n = 1491) was conducted at 23 secondary schools (14 Government, 4 Catholic, 5 Independent) in metropolitan Melbourne, Australia, to identify community-based adolescents with high levels of self-reported sleeping problems (score > 4 on the Pittsburgh Sleep Quality Index; PSQI) and anxiety symptoms (score > 32 males/ > 38 female on the Spence Children’s Anxiety Scale; SCAS). Consenting participants who met screening criteria (n = 218) completed semi-structured diagnostic clinical interview (Kiddie-Schedule for Affective Disorders and Schizophrenia for school-age children-Present and Lifetime version; K-SADS-PL) at the University of Melbourne, primarily to exclude individuals (n = 30) with a lifetime history of MDD, consistent with the study’s aim to prevent first onset depression. Eligible participants (n = 144) were randomised (1:1 allocation on an individual basis, and conditions were balanced for age, gender and presence or absence of current anxiety disorder at baseline) to either a seven-week, face-to-face, multicomponent cognitive-behavioural and mindfulness-based group sleep improvement treatment intervention (Sleep SENSE; n = 71) or an attention-matched active control study skills intervention (Study SENSE; n = 73). The Sleep SENSE intervention aimed to address common sleep problems including insufficient sleep duration, prolonged sleep onset, and variability in sleep timing, and included anxiety management components to assist with managing anxiety during the pre-sleep period. Mental health and sleep were assessed using: the K-SADS-PL (for MDD and GAD diagnosis); the Center for Epidemiologic Studies-Depression scale (CES-D; depressive symptoms); the SCAS (anxiety symptoms); the PSQI (self-reported sleep onset latency, total sleep time, overall sleep quality); and week-long actigraphy with sleep diary (objective sleep onset latency, total sleep time, weekday bedtime intra-individual variability, and weekday-to-weekend bedtime shift). Assessments occurred on three occasions–pre-intervention, post-intervention, and two-years after the completion of the intervention. All outcome assessments were administered by researchers who were blind to participants’ intervention assignment. Statistical analyses: All analyses used a modified intention-to-treat approach. Specifically, the final analysed sample (n = 122, sleep treatment n = 62, control intervention n = 60; 60% female; M age = 14.5 years, SD = 0.95, range 12.04 to 16.31 years) included participants who were eligible for and started the interventions, including those who dropped out of the interventions or were lost to follow-up (n = 13) but excluded participants who were identified as ineligible after randomisation (n = 2) and those who were randomised but never started the interventions (sleep treatment n = 10, control intervention n = 10). Latent growth curve modelling with multiple mediation analysis was used to test the effect of condition (i.e., sleep treatment or control intervention) on the long-term depression (i.e., presence or absence of MDD diagnosis, and severity of depressive symptoms) and anxiety (i.e., presence or absence of GAD diagnosis, and severity of anxiety symptoms) outcomes via improvements in the seven sleep variables immediately post-intervention (i.e., ‘initial status’ which was centred at the post-intervention time point) and over the two-year follow-up period (i.e., average linear ‘rate of change’ scaled to represent change per year). That is, the latent growth process of a sleep variable (i.e., the latent variables of initial status and rate of change) was used the mediator in the tested models. In total, 28 separate models were estimated using Mplus (Version 7) software using maximum likelihood estimation with robust standard errors. Results: Regarding the primary outcomes, there was no statistical evidence that the sleep treatment intervention improved subjective or objective indices of sleep immediately post-intervention or over the two-year follow-up period, or significantly predicted the presence or absence of major depressive disorder during, or reductions in depressive symptoms at, the two-year follow-up, relative to the active control intervention. Regarding the secondary outcome, the sleep treatment intervention did not significantly predict reductions on anxiety symptoms at two-year follow-up. However, the sleep treatment intervention significantly reduced the conditional odds of having GAD during the two-year follow-up period by a factor of seven on average, relative to the active control intervention, although confidence intervals suggested a small effect. There were no statistically significant indirect effects in any of the model investigated. Regardless of condition, participants’ subjective (B = -1.77, 95% CI [-3.47, -0.07]) and objective (B = -4.53, 95% CI [-7.96, -1.10]) sleep onset latency and subjective total sleep time (B = -0.18, 95% CI [-0.31, -0.05]) decreased over time, and weekday bedtime intra-individual variability increased over time (B = 7.99, 95% CI [2.11, 13.86]). In addition, poorer subjective sleep quality (B = 1.46, 95% CI [0.38, 2.54]) and less objective total sleep time (B = -3.31, 95% CI [-6.33, -0.28]) immediately post-intervention predicted depressive symptoms at two-year follow-up, and reductions in weekday bedtime intra-individual variability over time were associated with a decreased likelihood of GAD during the two-year follow-up (B = -0.52, 95% CI [-0.86, -0.18]). Conclusions: Together, the findings do not support the long-term efficacy of a targeted multicomponent cognitive-behavioural and mindfulness-based group sleep intervention for the improvement of sleep problems and prevention of first onset major depressive disorder in a community-based sample of at-risk adolescents. However, they tentatively suggest that anxiety may be more responsive to the sleep intervention than depression. In the context of a robust study design, the findings are hypothesis-generating and raise important considerations for the design of future clinical trials investigating the role of adolescent sleep interventions on emerging psychopathology. Funding: Australian National Health and Medical Research Council Grant (APP1027076). Trial Registration: Australian New Zealand Clinical Trials Registry (ACTRN12612001177842; prospectively registered on 6th November 2012).
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ItemThe psychological significance of different adolescent perfectionist profiles( 2018)Perfectionism has historically been regarded as a significant risk factor in the development and maintenance of psychological disorders. However, perfectionism is not always associated with poor psychological outcomes. Indeed, contemporary multidimensional perfectionism questionnaires include both adaptive and maladaptive dimensions, and recent research suggests a better understanding of perfectionism is achieved by focusing on combinations of these dimensions (rather than individual dimensions) to identify adaptive and maladaptive perfectionist subgroups/profiles. The purpose of the research reported herein was to investigate the nature of these subgroups in adolescents. Study 1 (n = 105, 17-year-olds) (Sironic & Reeve, 2012) examined perfectionist subgroups based on the Almost Perfect Scale-Revised (APS-R: Slaney, Rice, Mobley, Trippi, & Ashby, 2001), as well as the Depression Anxiety Stress Scales (DASS: Lovibond & Lovibond, 1995) and Motivated Strategies for Learning Questionnaire (Pintrich, Smith, Garcia, & McKeachie, 1991). It was hypothesised that four meaningful perfectionist subgroups could be derived from the APS-R’s High Standards and Discrepancy dimensions, and that each subgroup would rate their anxiety, depression, stress, and learning metacognitive beliefs differently. As predicted, cluster analysis of High Standards and Discrepancy dimension responses yielded four subgroup profiles: (1) high High Standards/low Discrepancy; (2) high High Standards/high Discrepancy; (3) low High Standards/high Discrepancy, and; (4) low High Standards/low Discrepancy). Subgroups were related to psychopathological symptoms and learning metacognitions in predictable ways. The low High Standards/high Discrepancy subgroup claimed to use metacognitive self-regulation significantly less often than the high High Standards/low Discrepancy and high High Standards/High Discrepancy subgroups; and the two high Discrepancy subgroups exhibited significantly higher depression ratings than the high High Standards/low Discrepancy subgroup. These findings support a four-subgroup account of perfectionism. The findings were interpreted as suggesting that the low High Standards/high Discrepancy subgroup might lack insight into (or deny) their perfectionistic tendencies—a tendency often associated with psychological disorders. Some suggest that perfectionism may be either externally and/or internally motivated. Insofar as this is correct, it is possible that students in this fourth subgroup are not seeking their own high standards but adopting the standards of significant others. Study 2 was designed to investigate this possibility. In Study 2 (n = 938, 14- to 17-year-olds) (Sironic & Reeve, 2015), high school students completed three commonly used perfectionism questionnaires (i.e., the Frost Multidimensional Perfectionism Scale, FMPS: Frost, Marten, Lahart, & Rosenblate, 1990; Child and Adolescent Perfectionism Scale, CAPS: Flett, Hewitt, Boucher, Davidson Munro, 2000; and APS-R), as well as the DASS. Preliminary analyses revealed commonly observed factor structures for each perfectionism questionnaire. Exploratory factor analysis of item responses from the three questionnaires (combined) yielded a four-factor solution (factors were labelled High Personal Standards, Concerns, Doubts and Discrepancy, Externally Motivated Perfectionism, and Organisation and Order). A latent class analysis of individuals’ mean ratings on each of the four factors yielded a six-class solution. Three of the six classes represented perfectionist subgroups (labelled adaptive perfectionist, externally motivated maladaptive perfectionist, and mixed maladaptive perfectionist) and three non-perfectionist subgroups (labelled non-perfectionist A, non-perfectionist B, and order and organisation non-perfectionist). Each subgroup was meaningfully associated with depression, anxiety, and stress symptoms. The mixed maladaptive perfectionist and externally motivated maladaptive perfectionist subgroups reported significantly higher levels of self-reported depression, anxiety, and stress compared with the adaptive perfectionist and non-perfectionist subgroups. The mixed maladaptive perfectionist and externally motivated maladaptive perfectionist subgroups did not differ in their depression and anxiety ratings, but the mixed maladaptive perfectionist subgroup reported significantly greater levels of stress than the externally motivated maladaptive perfectionist subgroup. The same three perfectionism questionnaires used in Study 2 were used in Study 3 (n = 299, 19-year-olds) (Sironic, Paul, & Reeve, under review at the time of thesis submission). Study 3 sought to establish whether externally motivated perfectionism was also an important aspect in a university undergraduate sample, and whether perfectionists’ beliefs about thinking (their clinical metacognitive beliefs, as measured by the Meta-Cognitions Questionniare-30 Shortened Version (MCQ-30: Wells & Cartwright-Hatton, 2004)) may differentiate perfectionist subgroups and help better explain their DASS depression, anxiety, and stress symptoms. Study 2’s four-factor solution was confirmed by factor analysis of items from the three perfectionism questionnaires, and the same three perfectionist subgroups were identified using latent class analysis of individuals’ average ratings on each factor. Clinical metacognitive beliefs and depression, anxiety, and stress ratings varied in expected ways in the different subgroups, with the externally motivated maladaptive perfectionists at greatest risk of poor psychological outcomes. Overall, the findings of the three studies offer new insights into the conceptualisation of adolescent perfectionism. Support was found for the existence of three perfectionist subgroups (one adaptive, two maladaptive) in adolescence. Findings showed that three out of 10 students were classified as maladaptive perfectionists, and that maladaptive perfectionists were more prevalent than adaptive perfectionists. Notably, the externally motivated maladaptive perfectionist subgroup seemed to possess the poorest metacognitive skills and be most at risk of experiencing psychopathology symptoms. These findings have implications for the treatment of perfectionists. They suggest that intervention strategies are needed to address issues associated with externally motivated perfectionism (i.e., the impact of parents, teachers or significant others); and that enhancing metacognitive skills could be included as part of an intervention strategy.
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ItemPsychological and neurobiological mechanisms underpinning chronic tinnitus( 2017)Chronic tinnitus, the phenomenon of a ringing, buzzing or hissing type sound in the ears or head is a prevalent health condition affecting 10-15% of the general population (Henry, Dennis, & Schechter, 2005a). It can have significant negative effects on an individual’s health and wellbeing and is associated with significant economic burden (Maes, Cima, Vlaeyen, Anteunis, & Joore, 2013; Tyler & Baker, 1983). At present, there is no cure for chronic tinnitus, likely due to the lack of consensus regarding the mechanisms maintaining the presence or impact of chronic tinnitus on individuals experiencing this condition. This thesis aimed to determine if psychological factors, and associated neural networks, could be maintaining awareness of the tinnitus sound and the severity of its impact. To achieve this objective, four studies were conducted utilising meta-analytic, questionnaire, cognitive and neuroimaging techniques. The first study comprehensively and systematically reviewed current literature regarding the psychological functioning of adults with chronic tinnitus. Results suggest that a heterogeneous array of psychological functions may be involved in the experience of chronic tinnitus, particularly emotional and cognitive functions, with meta-analyses providing consistent evidence for a role of reduced emotional wellbeing in both the presence and impact of chronic tinnitus. Study 2 and 3 further investigated the role of emotional and cognitive factors respectively in chronic tinnitus. Specifically, Study 2 investigated possible interactions between psychological factors and the vicious cycle of hypervigilance to the tinnitus sound in a heterogeneous community sample of 81 adults with chronic tinnitus. While analyses replicated the presence of the vicious cycle, this was conditional on the experience of depressive symptoms. Study 3 aimed to determine the contribution of cognitive functioning to chronic tinnitus. Compared to healthy-hearing individuals (n=26) people with chronic tinnitus (n=26) showed significant impairments in cognitive control, inhibitory control and increased symptoms of depression, with depressive symptoms and cognitive control successfully discriminating between people with and without chronic tinnitus. Combined, these studies suggest that disruption of specific large-scale neurocognitive networks proposed to underpin a range of psychological and cognitive symptoms; particularly those associated with depression may also underpin chronic tinnitus. As such, the final study of this thesis investigated the functioning of our stable neurocognitive networks, specifically the cognitive control network, in people with chronic tinnitus (n=15) and matched controls (n=15). While both groups successfully engaged the cognitive control network, the chronic tinnitus group exhibited subtle disruptions to a core node of this network, namely the right middle frontal gyrus, revealing both attenuated activation during cognitive engagement. This region also showed decreased connectivity with a node of the salience network, the right anterior insula, and increased connectivity with nodes of the autobiographical memory network, namely left posterior cingulate cortex and left medial prefrontal cortex. Together, the results of this thesis identify a failure in the process of attention-switching and the associated neurocognitive networks as a core mechanism underpinning the persistent awareness and pervasive impact of chronic tinnitus. This provides a novel framework, the Attention-Switching Model, for investigating both the experience of tinnitus, and potential treatments to help people with chronic tinnitus.
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ItemImproving depressive symptoms in adults with vision impairment: a trial of evidence-based ‘Problem-Solving Treatment' integrated within low vision rehabilitation services( 2017)Depression is exceedingly prevalent in people with vision impairment (VI), which further exacerbates vision-related functioning, disability and quality of life when left untreated.1-5 Up to 43% of people with VI experience depressive symptoms,6-11 although only one fifth of those receive psychological intervention.11 12 The main objective of this thesis was to evaluate the feasibility, effectiveness and implementation of evidence-based Problem-Solving Treatment for Primary Care (PST-PC) integrated into low vision rehabilitation (LVR) services. In this model, LVR staff were trained to deliver PST-PC via telephone to adult clients identified as showing depressive symptoms. To achieve the overall study objective, a multi-phase, mixed-methods approach was undertaken. In Phase 1, the evidence-base to support the integration of staff-delivered PST-PC in LVR services was delineated by conducting a review of the literature on depression and VI and a systematic review of the effectiveness of problem-solving interventions in this population. The findings underscored the need for pragmatic trials with longer-term follow-up to better understand the suitability of evidence-based problem-solving interventions delivered in routine LVR practice. In Phase 2, the feasibility, acceptability and preliminary data for the effectiveness of PST-PC was investigated. Fourteen LVR staff were trained to deliver PST-PC following a 2-day training workshop and training cases under psychologist supervision. Training cases were 18 LVR clients who received 6 to 8 sessions of PST-PC and participated in a single-group pre-post intervention study. Post intervention, 67% of client participants demonstrated a clinically significant change (CSC; >5-point reduction on the Patient Health Questionnaire-9 (PHQ-9)) in depressive symptoms. PST-PC was found to be highly acceptable to clients with 83% reporting that they were very satisfied with PST-PC. Concerns were raised by both staff and clients regarding telephone delivery and the client retention rate for PST-PC was low (60% completed <6 sessions). The main objective of Phase 3 was to investigate the clinical and cost-effectiveness of this model using a pragmatic, two-arm randomised controlled trial. Adult LVR clients with depressive symptoms (PHQ-9 score >5) were recruited from 28 LVR centres in Australia and randomised to receive PST-PC plus usual care (N=81) or usual care alone (N=82; referral to a general practitioner). In the intention-to-treat (ITT) analysis of the primary outcome (reduced depressive symptoms at 6 months on the PHQ-9), a large treatment effect was found (Cohen’s d (d) = -0.81, 95% CI -1.15 to -0.46) and 40% of the intervention group achieved a CSC compared to 14% of controls (odds ratio (OR) 5.72, 95% CI 1.61 to 20.36). Treatment effects were not maintained at 12 months in ITT analysis, but a significant group difference was found using the per-protocol sample (completed >4 sessions; d=0.59, 95% CI -1.09 to -0.08). ITT analysis of the secondary outcomes found greater improvements in HRQoL (Assessment of Quality of Life; d=0.39, 95% CI 0.05 to 0.72) and vision-specific distress (Impact of Vision Impairment Questionnaire; d=0.40, 95% CI 0.07 to 0.73) in the intervention group at 6 but not at 12 months. The PST-PC model was cost-effective according to commonly used willingness-to-pay thresholds in Australia (incremental cost effectiveness ratio: AU$40,386 (bootstrapped 95% CI: 20,580 to 355,190) per quality-adjusted life years gained). The aim of Phase 4 was to investigate and explore contextual factors associated with implementation of PST-PC in this setting. Given the low rate of participant retention with PST-PC in the RCT (79% completed <6 sessions), pre-treatment demographic, clinical and psychological predictors associated with early termination were investigated. 81 participants randomised to the intervention arm completed baseline and 6-month follow-up telephone assessments. Early termination was associated with being single (OR=8.77, 95% CI 2.15 to 35.66, p=0.002), having low perceived adequacy of social support (OR=0.48, 95% CI 0.30 to 0.75, p=0.001) and low acceptance of vision loss (OR=0.72, 95% CI 0.54 to 0.96, p=0.027). Staff perspectives on the barriers and facilitators to PST-PC delivery were also explored in Phase 4. Guided by theoretical frameworks that seek to evaluate implementation research,13 14 22 key project staff participated in semi-structured qualitative interviews. Prominent barriers to delivery were a lack of role recognition for PST-PC practitioners (n=32), perceived unmet client expectation with PST-PC (n=28) and dissatisfaction with telephone-delivery (n=27). Facilitating factors included a recognised need for evidence-based psychological services (n=28), clients experiencing benefits in early sessions (n=38) and comprehensive PST-PC training (n=36). In summary, this thesis supports the feasibility, clinical and cost-effectiveness of this integrated model for reducing depressive symptoms experienced by people attending Australian LVR centres. Strategies to improve retention with PST-PC are needed to ensure sufficient numbers achieve longer-term clinical benefit. Future research should also give attention as to whether staff-delivered PST-PC is scalable (or sustainable) and to developing services which are accessible to those who do not utilise LVR services (e.g. collaborative care models).
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ItemThe SENSE study (Sleep and Education: learning New Skills Early): postintervention effects of a randomised controlled trial of a cognitive-behavioural and mindfulness-based group sleep improvement intervention among at-risk adolescents( 2016)Objective: There is growing recognition that many adolescents obtain insufficient and/or poor quality sleep. Sleep problems are also a major risk factor for the emergence of mental health problems in adolescence. However, few studies have examined disturbed sleep as a potential mechanism in the treatment and prevention of mental health problems among adolescents. Adolescent sleep problems can be treated using a range of approaches. School-based sleep education programs, which are typically delivered to whole school classes, have been shown to have little impact on sleep behaviour or mental health. Cognitive-behavioural and mindfulness-based sleep programs, which are typically delivered to at-risk or already symptomatic adolescents, have been shown to be more effective in improving sleep and emotional distress, but studies evaluating their effectiveness have been limited in several ways, including small sample sizes and inadequate/lack of control groups. We conducted a systematic review and meta-analysis examining the efficacy of cognitive-behavioural sleep interventions among adolescents. Searches of PubMed, PsycINFO, CENTRAL, EMBASE, and MEDLINE were performed from inception to 1 May 2016. Eight trials were selected (n=234, mean age=15.24 years; female=63.18%). Main outcomes were subjective (sleep diary/questionnaire) and objective (actigraphy) total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), and wake after sleep onset (WASO). There was a small number of randomised controlled trials (RCTs; n=3), and a high risk of bias across the RCTs; therefore within sleep condition meta-analyses were examined. At post-intervention, subjective TST improved by 29.47 minutes (95% CI = 17.18, 41.75), SOL by 21.44 minutes (95% CI = -30.78, -12.11), SE by 5.34% (95% CI = 2.64, 8.04), and WASO by a medium effect size (d = 0.59 [95% CI = 0.36, 0.82). Objective SOL improved by 16.15 minutes (95% CI = -26.13, -6.17), and SE by 2.82% (95% CI = 0.58, 5.07). Global sleep quality, daytime sleepiness, depression, and anxiety also improved. Gains were generally maintained over time. Our meta-analysis provides preliminary evidence that cognitive-behavioural sleep interventions are an effective treatment for adolescent sleep problems, producing clinically meaningful responses within active treatment conditions. Their efficacy is maintained over time, and results in significant alleviation of sleep problems and improvement in functional outcomes. However, further large-scale, high-quality RCTs are needed to confirm these findings. The aim of this thesis was to investigate the post-intervention effects of a cognitive-behavioural/mindfulness-based group sleep intervention on sleep, mental health, and cognitive style among at-risk adolescents. The study went beyond simply measuring treatment outcomes to also evaluate mechanisms of change. Based on the behavioural, cognitive, hyperarousal, and transdiagnostic models of insomnia, a number of specific mediators were hypothesised to account for therapeutic change in cognitive-behavioural and mindfulness-based sleep interventions for adolescents, including earlier bedtimes, more consistent bedtimes, increased sleep hygiene awareness, and decreased dysfunctional beliefs and attitudes about sleep, worry, rumination, pre-sleep arousal, anxiety, and depression. Method: A RCT was conducted across Victorian secondary schools in Melbourne, Australia. Adolescents (aged 12-17 years) were recruited using a two-stage procedure, consisting of an in-school screening (n=1491) followed by a diagnostic interview for those meeting screening criteria (n=218), to identify students with high levels of anxiety and sleeping difficulties, but without past or current major depressive disorder (n=144). Eligible participants were randomised into either a sleep improvement intervention (‘Sleep SENSE’) or an active control ‘study skills’ intervention (‘Study SENSE’). One hundred twenty three participants began the interventions (Female=60%; Mean Age=14.48, SD=0.95), with 60 in the sleep condition and 63 in the control condition. All participants were required to complete a battery of mood, sleep and cognitive style questionnaires, seven-days of wrist actigraphy (an objective measurement of sleep), and sleep diary entry at pre-and-post intervention. Results: The sleep intervention condition was associated with significantly greater improvements in subjective sleep (global sleep quality, sleep onset latency, daytime sleepiness), objective sleep onset latency, anxiety, pre-sleep arousal, and sleep knowledge compared with the control intervention condition, with small-medium effect sizes. Parallel multiple mediation models showed that there were bidirectional relationships between improvements in subjective sleep quality and pre-sleep arousal/global anxiety. Conclusion: The SENSE study is an efficacy trial of a selective group-based sleep intervention for the treatment and prevention of sleep and mental health problems among at-risk adolescents experiencing both sleep and anxiety disturbance. The study provides evidence, using a methodologically rigorous design, including an active control comparison condition, that a multi-component group sleep intervention that includes cognitive-behavioural and mindfulness-based therapies, can improve wakefulness in bed variables, daytime dysfunction, anxiety, pre-sleep arousal, and sleep knowledge among at-risk adolescents. The results also provide evidence that pre-sleep arousal and anxiety are particularly important for adolescents’ perceived sleep quality, and should be key targets for new treatments of adolescent sleep problems. Public Health Significance: Given the high prevalence of adolescent sleep and internalising problems, the implications of an effective adolescent sleep intervention for clinical practice and public policy are potentially significant. However, changing sleep behaviour, especially objective measures of sleep, in this age group, has been challenging. This thesis shows that the Sleep-SENSE program can improve objective and subjective indices of sleep, as well as anxiety symptoms, when compared to an active control intervention. The results also showed that reductions in pre-sleep hyperarousal represent a key psychophysiological mechanism for therapeutic improvements in subjective sleep problems among anxious adolescents, and that cognitive behavioural and mindfulness-based sleep interventions should be directed towards adolescents with vulnerability for hyperarousal. Sleep SENSE is one of the only interventions demonstrated to be efficacious in improving sleep and mental health amongst vulnerable adolescents. Furthermore, the program is likely to be cost-effective - it involves a simple screening process and a group intervention format - and could be disseminated to a wide range of clinical and non-clinical settings in primary care, mental health, adolescent health and sleep medicine, and may assist in the treatment and prevention of adolescent sleep and mental health problems. The intervention also lends itself to flexible modes of delivery (e.g., non-specialist practitioners, group settings, individual settings, school-based, internet and other e-health modes of delivery), further enhancing its translational potential.
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ItemInvestigating anxiety and depression in adults with low intellectual ability( 2016)Adults with low ability have been routinely excluded from general population research that supports cognitive behavioural therapy for anxiety and depression. Even studies using samples of adults with ability below average exclude potential participants with profound and severe intellectual disability, without testing task-specific capacity. Consequently, little is known about the viability of cognitive models of anxiety and depression amongst adults with low ability. The present study addresses this through four main lines of enquiry: inclusion of all abilities through screening and validity procedures; prevalence of signs and symptoms of anxiety and depression as well as the impact of life stressors on these; cognitions and their specificity for anxiety and depression; and the impact of anxiety and ability on attentional responses to emotional stimuli. A sample of 70 adults from each level of low ability, unselected for signs or symptoms of anxiety and depression, was recruited from community-based disability support services. Participants were screened for general (receptive language) and task-specific abilities, interviewed for symptoms of anxiety and depression and disorder related cognitions then administered a visual-probe task with emotional face stimuli. Informants provided data on signs of mental ill-health, stressful life events and adaptive behaviour. Task-specific validity procedures governed data included for analysis. The inclusionary approach meant participants from all ability levels below average were included. Task-specific screening measures were superior to receptive language in predicting validity on research tasks, especially for participants with severe and profound intellectual disability. Dimensional measurements meant ability variables could be covaried or controlled in most analyses. Mean levels of signs and symptoms were lower than those in available reference studies, as were the rates of clinical level cases. General ability was positively correlated with signs of anxiety and depression but was not related to symptoms. Similarly, the number of life events was correlated with all scales on the measure of signs but not with symptoms of anxiety or depression. The lack of concordance highlights the gap between what informants see and what respondents think and feel. Learning a person’s subjective interpretation of events can help understand their emotions and behaviour. Depressive cognitions uniquely predicted significant variance in symptoms of depression but only ability, rather than anxious cognitions, predicted anxiety symptoms. Cognitive content-specificity for depression bolsters support for the use of cognitive behaviour therapy but further research into the relationship between ability and anxiety is required. The lack of directional bias in selective attention to emotional faces in any of the anxiety or ability groups means cognitive-motivational theory was not supported but future studies should address methodological issues. Attentional control theory was supported but the slowing of emotional face processing caused by high anxiety, but not depression needs replication. Trials of attentional training may be justified to reduce anxiety. Further research into cognitive models of anxiety and depression is urgently needed and future studies should ask theoretical as well as clinical questions.
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ItemTemperament change during adolescence: Normative growth trajectories and the association of temperament change and pubertal development factors with adolescent psychopathology( 2016)Purpose of the study: This study examined the nature of temperament change during adolescence, using a longitudinal design to describe normative changes and individual heterogeneity in the developmental trajectories of traits. The study design allowed for further investigation of whether individual changes in temperament are associated with specific risk for depressive disorders. Pubertal timing and tempo were examined as developmentally salient factors that may potentially contribute to individual level changes in traits, including changes associated with depressive disorders. Method: A community sample of 245 adolescents participated in the longitudinal assessment of four temperament traits (Affiliation, Effortful Control, Negative Emotionality, Surgency), using the Early Adolescent Temperament Questionnaire, across five time points from early adolescence (mean age 11.62 years) to late adolescence (mean age 18.88 years). Univariate and multivariate latent growth modelling approaches, including latent growth models, latent class growth models and growth mixture models, were used to analyse normative and individual trajectories of temperament change. Adolescent depression was assessed via a questionnaire measure of symptoms and clinical interviewing to determine case level depressive disorders. To examine the specificity of associations between temperament and depression, questionnaire and interview measures were also used to assess adolescents’ broader risk for psychopathology, including anxiety and externalising symptoms and case level disorders. Pubertal timing and tempo were assessed during early adolescence using measures based on the Pubertal Development Scale. Results: Analyses of normative temperament trajectories revealed non-linear changes for Affiliation, Negative Emotionality and Surgency, reflecting both increases and decreases in temperament maturity during adolescence. The normative trajectory for Effortful Control showed linear decreases across adolescence. There was evidence of significant heterogeneity of temperament development, including individual differences in baseline levels of traits and in the degree and direction of change. The extent of heterogeneity was more sufficiently represented by significant individual level variance around univariate trajectories of normative change, rather than by sub-groups of individuals in multivariate models. Increased risk for depression was associated with lower baseline Surgency and Effortful Control, higher baseline Negative Emotionality and overall decreases in Affiliation, as well as relatively greater decreases in Effortful Control and slower decreases in Negative Emotionality compared with same age and gender peers. However, while specific risk for depressive disorders was associated with decreases in Affiliation during adolescence, further associations were observed between baseline levels and changes in traits with other categories of psychopathology. There was no evidence that pubertal timing and tempo are sources of temperament change during adolescence, however pubertal timing showed significant associations with adolescent psychopathology. Conclusions: This study contributes to existing literature on temperament that describes adolescence as a developmental period when normative temperament changes do not show overall increases in maturity. This study also highlights the need for further research to identify sources of temperament change during adolescence, as pubertal timing and temperament may be independent risk factors for psychopathology during adolescence. The findings add to accumulating evidence suggesting that changes in temperament influence an individual’s level of risk for adolescent psychopathology, over and above risk from baseline levels of traits. This includes evidence of temperament changes that confer specific risk for depression, including decreases in Affiliation, rather than general risk for psychopathology. Such findings may assist with targeting prevention or early intervention efforts against adolescent depression.
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ItemNeurocognitive and psychiatric markers of network disease in epilepsy( 2015)People with epilepsy frequently experience debilitating memory and mood difficulties. Autobiographic memory impairments are a vulnerability factor for developing and maintaining unipolar depression in the psychiatric population, yet despite the wealth of research examining cognition and behaviour in epilepsy, the links between them remain unclear. This thesis aimed to profile the autobiographic memory and mood function of patients with focal epilepsy relative to healthy controls, and characterise how these functions may be interlinked. Three behavioural studies were conducted to achieve these objectives. Participants were prospectively recruited from the Comprehensive Epilepsy Programme at Austin Health, Melbourne, between 2010-2014. The cognitive and psychiatric functioning of 85 adults with chronic focal epilepsy was compared to that of 72 sociodemographically-matched controls largely recruited from the patients’ families (N=157). Gold-standard psychometric measures assessed depressive symptoms and cognitive function. Study One was an initial qualitative exploration of the relationships between cognitive impairment and depression in a form of focal epilepsy not typically linked to memory disorder, to assess the effects of seizures and pathology on those functions. A well-characterised case series of nine patients with frontal lobe epilepsy (FLE) was contrasted to 24 matched controls. Results suggested that FLE can selectively interrupt the integrity of the autobiographic memory/cognitive control networks versus the affective network. Study Two aimed to quantitatively delineate the effects of seizure chronicity on impaired autobiographic memory in a large cohort of patients (n=85) relative to healthy controls (n=72), and the potential links between poor autobiographic recall and mood. This revealed that chronic seizures beginning in childhood dysregulate cognition-related networks important for autobiographic recall, while autobiographic memory impairments in patients with a more recent disease onset are largely linked to depressive symptoms, perhaps reflecting maladaptive psychological adjustment to the onset of epilepsy as an adult. Together, the first two studies show that autobiographic memory difficulties are only related to depression in certain epilepsy syndromes. Finally, Study Three comprised a data-driven investigation into the existence of a cognitive phenotype of depression in epilepsy. Results showed that of the 21 (25%) patients currently meeting criteria for a formal depressive disorder, 15 (71%) had a ‘Cognitive’ phenotype of the disorder, while six (29%) presented with a ‘Somatic’ phenotype. These findings are congruent with phenotypes of depression found in other populations, and suggest that different presentations of depression in epilepsy may uniquely index dysregulation of selected brain networks. Moreover the lack of seizure-related correlates to the Cognitive phenotype discounts the widespread assumption that cognitive and affective network dysfunction in epilepsy is a side-effect of seizures. The results of this thesis suggest that epilepsy can selectively disrupt large-scale brain networks important to cognition and affect, and that behavioural disturbances in people with epilepsy may be primary manifestations of the network disease.