Psychiatry - Research Publications
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ItemNo Preview AvailableBrain Correlates of Suicide Attempt in 18,925 Participants Across 18 International Cohorts(ELSEVIER SCIENCE INC, 2021-08-15)BACKGROUND: Neuroimaging studies of suicidal behavior have so far been conducted in small samples, prone to biases and false-positive associations, yielding inconsistent results. The ENIGMA-MDD Working Group aims to address the issues of poor replicability and comparability by coordinating harmonized analyses across neuroimaging studies of major depressive disorder and related phenotypes, including suicidal behavior. METHODS: Here, we pooled data from 18 international cohorts with neuroimaging and clinical measurements in 18,925 participants (12,477 healthy control subjects and 6448 people with depression, of whom 694 had attempted suicide). We compared regional cortical thickness and surface area and measures of subcortical, lateral ventricular, and intracranial volumes between suicide attempters, clinical control subjects (nonattempters with depression), and healthy control subjects. RESULTS: We identified 25 regions of interest with statistically significant (false discovery rate < .05) differences between groups. Post hoc examinations identified neuroimaging markers associated with suicide attempt including smaller volumes of the left and right thalamus and the right pallidum and lower surface area of the left inferior parietal lobe. CONCLUSIONS: This study addresses the lack of replicability and consistency in several previously published neuroimaging studies of suicide attempt and further demonstrates the need for well-powered samples and collaborative efforts. Our results highlight the potential involvement of the thalamus, a structure viewed historically as a passive gateway in the brain, and the pallidum, a region linked to reward response and positive affect. Future functional and connectivity studies of suicidal behaviors may focus on understanding how these regions relate to the neurobiological mechanisms of suicide attempt risk.
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ItemEditorial: Early Intervention in Mood Disorders(FRONTIERS MEDIA SA, 2021-12-09)
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ItemNo Preview AvailableAltered resting-state functional connectome in major depressive disorder: a mega-analysis from the PsyMRI consortium(SPRINGERNATURE, 2021-10-07)Major depressive disorder (MDD) is associated with abnormal neural circuitry. It can be measured by assessing functional connectivity (FC) at resting-state functional MRI, that may help identifying neural markers of MDD and provide further efficient diagnosis and monitor treatment outcomes. The main aim of the present study is to investigate, in an unbiased way, functional alterations in patients with MDD using a large multi-center dataset from the PsyMRI consortium including 1546 participants from 19 centers ( www.psymri.com ). After applying strict exclusion criteria, the final sample consisted of 606 MDD patients (age: 35.8 ± 11.9 y.o.; females: 60.7%) and 476 healthy participants (age: 33.3 ± 11.0 y.o.; females: 56.7%). We found significant relative hypoconnectivity within somatosensory motor (SMN), salience (SN) networks and between SMN, SN, dorsal attention (DAN), and visual (VN) networks in MDD patients. No significant differences were detected within the default mode (DMN) and frontoparietal networks (FPN). In addition, alterations in network organization were observed in terms of significantly lower network segregation of SMN in MDD patients. Although medicated patients showed significantly lower FC within DMN, FPN, and SN than unmedicated patients, there were no differences between medicated and unmedicated groups in terms of network organization in SMN. We conclude that the network organization of cortical networks, involved in processing of sensory information, might be a more stable neuroimaging marker for MDD than previously assumed alterations in higher-order neural networks like DMN and FPN.
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ItemBroad clinical high-risk mental state (CHARMS): Methodology of a cohort study validating criteria for pluripotent risk(WILEY, 2019-06)AIM: The development of the ultra-high risk (UHR) criteria for psychosis created a new paradigm for the prevention research in psychiatry. Since (1) prevention research faces the challenge of achieving adequate statistical power when focusing on single low-incidence syndromes and (2) early clinical phenotypes are overlapping and non-specific, this study broadens the UHR state beyond psychosis as an outcome. The CHARMS (clinical high at-risk mental state) study aims to prospectively validate a set of trans-diagnostic criteria to identify help-seeking young people at risk of developing a range of serious mental illnesses. METHODS: This paper describes the methodology of the CHARMS study, which involves applying the CHARMS criteria to a cohort of help-seeking young people aged 12 to 25 attending youth mental health services in Melbourne. New referrals meeting the CHARMS criteria are allocated to the CHARMS+ group; referrals not meeting CHARMS threshold are allocated to CHARMS- group (control group); referrals meeting criteria for a full-threshold disorder are excluded. Transition status and clinical and functional outcomes are re-assessed at 6 and 12 months. CONCLUSIONS: This study will be the first to introduce and validate clinical criteria to identify a broader at-risk patient population, which may facilitate young people's access to clinical services and early treatment by reducing the reliance on "caseness" defined according to current diagnostic categories being required for service entry. These criteria may introduce a new, trans-diagnostic approach for understanding risk factors and pathogenic mechanisms that drive the onset of severe mental illness and the next generation of preventive intervention trials.
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ItemA systematic review and meta-analysis of prospective transition from major depression to bipolar disorder(WILEY, 2017-04)OBJECTIVE: Some people with major depressive disorder (MDD) may be at a pre-onset stage for bipolar disorder (BD), where early identification or prevention efforts may be feasible. We aimed to identify rates and characteristics predictive of transition to BD in prospective follow-up studies of people with MDD. METHODS: Using a systematic search strategy, we identified studies with a diagnostic ascertainment of MDD and BD of an adequate standard, and where the minimum length of follow-up was 6 months. We examined the incidence and point prevalence of BD and the pooled odds ratios (OR) for baseline predictors. RESULTS: From 5554 unique publications, 56 were included. Nearly a quarter of adults (22.5%) and adolescents with MDD followed up for a mean length of 12-18 years developed BD, with the greatest risk of transition being in the first 5 years. The meta-analysis identified that transition from MDD to BD was predicted by family history of BD (OR = 2.89, 95% CI: 2.01-4.14, N = 7), earlier age of onset of depression (g = -0.33, SE = 0.05, N = 6) and presence of psychotic symptoms (OR = 4.76, 95% CI: 1.79-12.66, N = 5). CONCLUSIONS: Participants with the identified risk factors merit closer observation and may benefit from prevention efforts, especially if outcomes broader than BD are considered.
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ItemIntegrating family work into the treatment of young people with severe and complex depression: a developmentally focused model(WILEY, 2018-04)AIM: Although models of family intervention are clearly articulated in the child and early adolescent literature, there is less clarity regarding family intervention approaches in later adolescence and emerging adulthood. METHODS: This study provides the rationale and intervention framework for a developmentally sensitive model of time-limited family work in the outpatient treatment of complex youth depression (15-25 years). RESULTS: Derived from current practice in the Youth Mood Clinic (YMC) at Orygen Youth Health, Melbourne, a stepped model of family intervention is discussed. YMC aims to provide comprehensive orientation, assessment and education to all families. For some, a family-based intervention, delivered either by the treating team or through the integration of a specialist family worker, offers an important adjunct in supporting the recovery of the young person. Developmental phases and challenges experienced by the young person with respect to family/caregiver involvement are discussed in the context of two case studies. CONCLUSIONS: A developmentally sensitive model is presented with particular attention to the developmental needs and preferences of young people. Formal evaluation of this model is required. Evaluation perspectives should include young people, caregivers, the broader family system (i.e. siblings) and the treating team (i.e. case manager, doctor and family worker) incorporating outcome measurement. Such work determines how best to apply a time-limited family-based intervention approach in strengthening family/caregiver relationships as part of the young person's recovery from severe and complex depression.
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ItemModerated online social therapy for depression relapse prevention in young people: pilot study of a "next generation' online intervention(WILEY, 2018-08)AIM: Implementation of targeted e-mental health interventions offers a promising solution to reducing the burden of disease associated with youth depression. A single-group pilot study was conducted to evaluate the acceptability, feasibility, usability and safety of a novel, moderated online social therapy intervention (entitled Rebound) for depression relapse prevention in young people. METHODS: Participants were 42 young people (15-25 years) (50% men; mean age = 18.5 years) in partial or full remission. Participants had access to the Rebound platform for at least 12 weeks, including the social networking, peer and clinical moderator and therapy components. RESULTS: Follow-up data were available for 39 (92.9%) participants. There was high system usage, with 3034 user logins (mean = 72.2 per user) and 2146 posts (mean = 51.1). Almost 70% of users had ≥10 logins over the 12 weeks, with 78.5% logging in over at least 2 months of the pilot. A total of 32 (84%) participants rated the intervention as helpful. There was significant improvement between the number of participants in full remission at baseline (n = 5; none of whom relapsed) relative to n = 19 at 12-week follow-up (P < 0.001). Six (14.3%) participants relapsed to full threshold symptoms at 12 weeks. There was a significant improvement to interviewer-rated depression scores (Montgomery-Asberg Depression Rating Scale (MADRS); P = 0.014, d = 0.45) and a trend for improved strength use (P = 0.088, d = 0.29). The single-group design and 12-week treatment phase preclude a full understanding of the clinical benefits of the Rebound intervention. CONCLUSIONS: The Rebound intervention was shown to be acceptable, feasible, highly usable and safe in young people with major depression.
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ItemEthical considerations in preventive interventions for bipolar disorder(WILEY, 2017-04)AIM: Early intervention and prevention of serious mental disorders such as bipolar disorder has the promise of decreasing the burden associated with these disorders. With increasing early and preventive intervention efforts among cohorts such as those with a familial risk for bipolar disorder, there is a need to examine the associated ethical concerns. The aim of this review was to examine the ethical issues underpinning the clinical research on pre-onset identification and preventive interventions for bipolar disorder. METHODS: We undertook a PubMed search updated to November 2014 incorporating search terms such as bipolar, mania, hypomania, ethic*(truncated), early intervention, prevention, genetic and family. RESULTS: Fifty-six articles that were identified by this method as well as other relevant articles were examined within a framework of ethical principles including beneficence, non-maleficence, respect for autonomy and justice. The primary risks associated with research and clinical interventions include stigma and labelling, especially among familial high-risk youth. Side effects from interventions are another concern. The benefits of preventive or early interventions were in the amelioration of symptoms as well as the possibility of minimizing disability, cognitive impairment and progression of the illness. Supporting the autonomy of individuals and improving access to stigma-free care may help moderate the potential challenges associated with the risks of interventions. CONCLUSIONS: Concerns about the risks of early identification and pre-onset interventions should be balanced against the potential benefits, the individuals' right to choice and by improving availability of services that balance such dilemmas.
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ItemNo Preview AvailableNeural mediators of subjective and autonomic responding during threat learning and regulation(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2021-12-15)Threat learning elicits robust changes across multiple affective domains, including changes in autonomic indices and subjective reports of fear and anxiety. It has been argued that the underlying causes of such changes may be dissociable at a neural level, but there is currently limited evidence to support this notion. To address this, we examined the neural mediators of trial-by-trial skin conductance responses (SCR), and subjective reports of anxious arousal and valence in participants (n = 27; 17 females) performing a threat reversal task during ultra-high field functional magnetic resonance imaging. This allowed us to identify brain mediators during initial threat learning and subsequent threat reversal. Significant neural mediators of anxious arousal during threat learning included the dorsal anterior cingulate, anterior insula cortex (AIC), and ventromedial prefrontal cortex (vmPFC), subcortical regions including the amygdala, ventral striatum, caudate and putamen, and brain-stem regions including the pons and midbrain. By comparison, autonomic changes (SCR) were mediated by a subset of regions embedded within this broader circuitry that included the caudate, putamen and thalamus, and two distinct clusters within the vmPFC. The neural mediators of subjective negative valence showed prominent effects in posterior cortical regions and, with the exception of the AIC, did not overlap with threat learning task effects. During threat reversal, positive mediators of both subjective anxious arousal and valence mapped to the default mode network; this included the vmPFC, posterior cingulate, temporoparietal junction, and angular gyrus. Decreased SCR during threat reversal was positively mediated by regions including the mid cingulate, AIC, two sub-regions of vmPFC, the thalamus, and the hippocampus. Our findings add novel evidence to support distinct underlying neural processes facilitating autonomic and subjective responding during threat learning and threat reversal. The results suggest that the brain systems engaged in threat learning mostly capture the subjective (anxious arousal) nature of the learning process, and that appropriate responding during threat reversal is facilitated by participants engaging self- and valence-based processes. Autonomic changes (SCR) appear to involve distinct facilitatory and regulatory contributions of vmPFC sub-regions.
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ItemNo Preview AvailableClarifying the neural substrates of threat and safety reversal learning in humans(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2020-02-15)Responding flexibly to sources of threat and safety is critical to the adaptive regulation of emotions, including fear. At a neural systems level, such flexibility is thought to rely on an extended neural circuitry involving the dorsal anterior cingulate cortex (dACC) and ventromedial prefrontal cortices (vmPFC), although precisely how this occurs remains unclear. Using a novel fear reversal task and functional magnetic resonance imaging (fMRI), we examined the neural correlates of threat and safety reversal learning and their associations with individual differences in anxious responding in a large sample of healthy adolescents and young adults. Overall, participants demonstrated successful threat and safety reversal learning, as indexed by subjective ratings. At a whole-brain level, threat reversal was associated with significant activation of the bilateral anterior insular cortex and dACC, in particular its rostral subregion. Conversely, safety reversal led to significant activation of the anterior vmPFC, together with posterior mid-line regions. Further analyses of regional responses suggested a more selective role for the rostral dACC in threat signal updating, as well as a direct association of its activity with participants' change in subjective anxious arousal to the reversed threat. Taken together, our findings complement existing neurocircuitry models of human fear regulation, particularly regarding the importance of midline cortical regions, and provide further insights into their specific contribution to flexible threat-safety signal processing. In particular, our results suggest that rostral dACC function may be more centrally involved in regulating levels of anxious arousal when flexibility is required. They also raise important questions regarding the vmPFC's role in safety learning, particularly involving its hypothesized subregional contributions to response inhibitory versus stimulus value processing functions.
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