Psychiatry - Research Publications

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    A potential role for N-acetylcysteine in the management of methamphetamine dependence
    McKetin, R ; Dean, OM ; Baker, AL ; Carter, G ; Turner, A ; Kelly, PJ ; Berk, M (WILEY, 2017-03)
    Methamphetamine dependence is a growing problem in Australia and globally. Currently, there are no approved pharmacotherapy options for the management of methamphetamine dependence. N-acetylcysteine is one potential pharmacotherapy option. It has received growing attention as a therapy for managing addictions because of its capacity to restore homeostasis to brain glutamate systems disrupted in addiction and thereby reduce craving and the risk of relapse. N-acetylcysteine also has antioxidant properties that protect against methamphetamine-induced toxicity and it may therefore assist in the management of the neuropsychiatric and neurocognitive effects of methamphetamine. This commentary overviews the actions of N-acetylcysteine and evidence for its efficacy in treating addiction with a particular focus on its potential utility for methamphetamine dependence. We conclude that the preliminary evidence indicates a need for full-scale trials to definitively establish whether N-acetylcysteine has a therapeutic benefit and the nature of this benefit, for managing methamphetamine dependence. [McKetin R, Dean O, Baker A. L, Carter G, Turner A, Kelly P. J, Berk M. A potential role for N-acetylcysteine in the management of methamphetamine dependence. Drug Alcohol Rev 2017;36:153-159].
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    Protocol and Rationale-The Efficacy of Minocycline as an Adjunctive Treatment for Major Depressive Disorder: A Double Blind, Randomised, Placebo Controlled Trial
    Dean, OM ; Maes, M ; Ashton, M ; Berk, L ; Kanchanatawan, B ; Sughondhabirom, A ; Tangwongchai, S ; Ng, C ; Dowling, N ; Malhi, GS ; Berk, M (KOREAN COLL NEUROPSYCHOPHARMACOLOGY, 2014-12)
    While current pharmacotherapies are efficacious, there remain a clear shortfall between symptom remission and functional recovery. With the explosion in our understanding of the biology of these disorders, the time is ripe for the investigation of novel therapies. Recently depression is conceptualized as an immune-inflammatory and nitro-oxidative stress related disorder. Minocycline is a tetracycline antibiotic that has anti-inflammatory, pro-oxidant, glutamatergic, neurotrophic and neuroprotective properties that make it a viable target to explore as a new therapy. This double blind, randomised, placebo controlled adjunctive trial will investigate the benefits of 200 mg/day of minocycline treatment, in addition to any usual treatment, as an adjunctive treatment for moderate-severe major depressive disorder. Sixty adults are being randomised to 12 weeks of treatment (with a 4 week follow-up post-discontinuation). The primary outcome measure for the study is mean change on the Montgomery-Asberg Depression Rating Scale (MADRS), with secondary outcomes including the Social and Occupational Functioning Assessment Scale (SOFAS), Clinical Global Impressions (CGI), Hamilton Rating Scale for Anxiety (HAM-A), Patient Global Impression (PGI), Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q) and Range of Impaired Functioning Tool (LIFE-RIFT). Biomarker analyses will also be conducted at baseline and week 12. The study has the potential to provide new treatment targets, both by showing efficacy with a new class of 'antidepressant' but also through the analysis of biomarkers that may further inform our understanding of the pathophysiology of unipolar depression.
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    Future Directions for Pharmacotherapies for Treatment-resistant Bipolar Disorder
    Dodd, S ; Fernandes, BS ; Dean, OM (BENTHAM SCIENCE PUBL LTD, 2015)
    Current pharmacological treatments for bipolar disorder (BD) are limited and efficacy has historically been discovered through serendipity. There is now scope for new drug development, focused on the underlying biology of BD that is not targeted by current therapies. The need for novel treatments is urgent when considering treatment resistant BD, where current therapies have failed. While established drugs targeting the monoamine systems continue to be worthwhile, new biological targets including inflammatory and oxidative an nitrosative pathways, apoptotic and neurotrophic pathways, mitochondrial pathways, the N-methyl-Daspartate (NMDA)-receptor complex, the purinergic system, neuropeptide system, cholinergic system and melatonin pathways are all being identified as potential anchors for the discovery of new agents. Many agents are experimental and efficacy data is limited, however further investigation may provide a new line for drug discovery, previously stalled by lack of corporate interest.
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    N-Acetyl Cysteine in the Treatment of Obsessive Compulsive and Related Disorders: A Systematic Review
    Oliver, G ; Dean, O ; Camfield, D ; Blair-West, S ; Ng, C ; Berk, M ; Sarris, J (KOREAN COLL NEUROPSYCHOPHARMACOLOGY, 2015-04)
    OBJECTIVE: Obsessive compulsive and related disorders are a collection of debilitating psychiatric disorders in which the role of glutamate dysfunction in the underpinning neurobiology is becoming well established. N-acetyl cysteine (NAC) is a glutamate modulator with promising therapeutic effect. This paper presents a systematic review of clinical trials and case reports exploring the use of NAC for these disorders. A further objective was to detail the methodology of current clinical trials being conducted in the area. METHODS: PubMed, Web of Science and Cochrane Library Database were searched for human clinical trials or case reports investigating NAC in the treatment of obsessive compulsive disorder (OCD) or obsessive compulsive related disorders. Researchers with known involvement in NAC studies were contacted for any unpublished data. RESULTS: Four clinical trials and five case reports/series were identified. Study durations were commonly 12-weeks, using 2,400-3,000 mg/day of NAC. Overall, NAC demonstrates activity in reducing the severity of symptoms, with a good tolerability profile and minimal adverse effects. Currently there are three ongoing randomized controlled trials using NAC for OCD (two adults and one pediatric), and one for excoriation. CONCLUSIONS: Encouraging results have been demonstrated from the few pilot studies that have been conducted. These results are detailed, in addition to a discussion of future potential research.
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    The efficacy of sodium benzoate as an adjunctive treatment in early psychosis - CADENCE-BZ: study protocol for a randomized controlled trial
    Ryan, A ; Baker, A ; Dark, F ; Foley, S ; Gordon, A ; Hatherill, S ; Stathis, S ; Saha, S ; Bruxner, G ; Beckman, M ; Richardson, D ; Berk, M ; Dean, O ; McGrath, J ; Scott, J (BIOMED CENTRAL LTD, 2017-04-07)
    BACKGROUND: Psychotic disorders affect up to 3% of the population and are often chronic and disabling. Innovation in the pharmacological treatment of psychosis has remained stagnant in recent decades. In order to improve outcomes for those with psychotic disorders, we present a protocol for the trial of a common food preservative, sodium benzoate, as an adjunctive treatment in early psychosis. METHODS: Persons experiencing early psychosis (n = 160) will be recruited through hospitals and community mental health services in Queensland, Australia. Patients will be randomized to receive either 12-week treatment with 1000 mg (500 mg twice daily (BD)) sodium benzoate or placebo. Patients will undergo fortnightly outcome assessments, in addition to weekly ongoing capacity to consent, drug compliance and safety assessments. The primary outcome measure is the Positive and Negative Syndrome Scale (PANSS) total score. Secondary outcomes are Global Assessment of Function (GAF), Assessment of Quality of Life Scale (AQOL), the Activity and Participation Questionnaire (APQ6), International Physical Activity Questionnaires (IPAQ), Simple Physical Activity Questionnaire (SIMPAQ), Physical Activity Questionnaire, Clinical Global Impression (CGI), Hamilton Depression rating Scale-17 items (HDRS), Opiate Treatment Index (OTI) and the Patients' Global Impression of Improvement (PGI-I). As a tertiary objective, changes from baseline to endpoint in to serum markers related to D-alanine, L-alanine, D-serine, L-serine, glycine and glutamate will be investigated. DISCUSSION: Consumers and clinicians are keen to help develop better treatments for those with psychosis. This study, part of the wider Cadence clinical trials platform will examine if a safe and accessible food preservative can help optimize outcomes in those with psychosis. TRIAL REGISTRATION: Australian New Zealand Clinical Trials registry (ANZCTR), ACTRN12615000187549 . Registered on 26 February 2015.
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    Mechanisms Underpinning the Polypharmacy Effects of Medications in Psychiatry
    Bortolasci, CC ; Spolding, B ; Callaly, E ; Martin, S ; Panizzutti, B ; Kidnapillai, S ; Connor, T ; Hasebe, K ; Mohebbi, M ; Dean, OM ; McGee, SL ; Dodd, S ; Gray, L ; Berk, M ; Walder, K (OXFORD UNIV PRESS, 2018-06)
    BACKGROUND: Bipolar disorder is a mental health condition with progressive social and cognitive function disturbances. Most patients' treatments are based on polypharmacy, but with no biological basis and little is known of the drugs' interactions. The aim of this study was to analyze the effects of lithium, valproate, quetiapine, and lamotrigine, and the interactions between them, on markers of inflammation, bioenergetics, mitochondrial function, and oxidative stress in neuron-like cells and microglial cells. METHODS: Neuron-like cells and lipopolysaccharide-stimulated C8-B4 cells were treated with lithium (2.5 mM), valproate (0.5 mM), quetiapine (0.05 mM), and lamotrigine (0.05 mM) individually and in all possible combinations for 24 h. Twenty cytokines were measured in the media from lipopolysaccharide-stimulated C8-B4 cells. Metabolic flux analysis was used to measure bioenergetics, and real-time PCR was used to measure the expression of mitochondrial function genes in neuron-like cells. The production of superoxide in treated cells was also assessed. RESULTS: The results suggest major inhibitory effects on proinflammatory cytokine release as a therapeutic mechanism of these medications when used in combination. The various combinations of medications also caused overexpression of PGC1α and ATP5A1 in neuron-like cells. Quetiapine appears to have a proinflammatory effect in microglial cells, but this was reversed by the addition of lamotrigine independent of the drug combination. CONCLUSION: Polypharmacy in bipolar disorder may have antiinflammatory effects on microglial cells as well as effects on mitochondrial biogenesis in neuronal cells.
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    Add-on treatment with N-acetylcysteine for bipolar depression: a 24-week randomized double-blind parallel group placebo-controlled multicentre trial (NACOS-study protocol)
    Ellegaard, PK ; Licht, RW ; Poulsen, HE ; Nielsen, RE ; Berk, M ; Dean, OM ; Mohebbi, M ; Nielsen, CT (SPRINGER, 2018-04-05)
    BACKGROUND: Oxidative stress and inflammation may be involved in the development and progression of mood disorders, including bipolar disorder. Currently, there is a scarcity of useful treatment options for bipolar depressive episodes, especially compared with the efficacy of treatment for acute mania. N-Acetylcysteine (NAC) has been explored for psychiatric disorders for some time given its antioxidant and anti-inflammatory properties. The current trial aims at testing the clinical effects of adjunctive NAC treatment (compared to placebo) for bipolar depression. We will also explore the biological effects of NAC in this context. We hypothesize that adjunctive NAC treatment will reduce symptoms of depression, which will be reflected by changes in selected markers of oxidative stress. METHODS AND ANALYSIS: In the study, we will include adults diagnosed with bipolar disorder, in a currently depressive episode. Participants will undertake a 20-week, adjunctive, randomized, double-blinded, parallel group placebo-controlled trial comparing 3 grams of adjunctive NAC daily with placebo. The primary outcome is the mean change over time from baseline to end of study on the Montgomery-Asberg Depression Rating Scale (MADRS). Among the secondary outcomes are mean changes from baseline to end of study on the Bech-Rafaelsen Melancholia Scale (MES), the Young Mania Rating Scale (YMRS), the WHO-Five Well-being Index (WHO-5), the Global Assessment of Functioning scale (GAF-F), the Global Assessment of Symptoms scale (GAF-S) and the Clinical Global Impression-Severity scale (CGI-S). The potential effects on oxidative stress by NAC treatment will be measured through urine and blood samples. DNA will be examined for potential polymorphisms related to oxidative defences. TRIAL REGISTRATION: Registered at The European Clinical Trials Database, ClinicalTrials.gov: NCT02294591 and The Danish Data Protection Agency: 2008-58-0035.
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    Mitochondrial Agents for Bipolar Disorder
    Pereira, C ; Chavarria, V ; Vian, J ; Ashton, MM ; Berk, M ; Marx, W ; Dean, OM (OXFORD UNIV PRESS, 2018-06)
    BACKGROUND: Bipolar disorder is a chronic and often debilitating illness. Current treatment options (both pharmaco- and psychotherapy) have shown efficacy, but for many leave a shortfall in recovery. Advances in the understanding of the pathophysiology of bipolar disorder suggest that interventions that target mitochondrial dysfunction may provide a therapeutic benefit. METHODS: This review explores the current and growing theoretical rationale as well as existing preclinical and clinical data for those therapies aiming to target the mitochondrion in bipolar disorder. A Clinicaltrials.gov and ANZCTR search was conducted for complete and ongoing trials on mitochondrial agents used in psychiatric disorders. A PubMed search was also conducted for literature published between January 1981 and July 2017. Systematic reviews, randomized controlled trials, observational studies, case series, and animal studies with an emphasis on agents affecting mitochondrial function and its role in bipolar disorder were included. The search was augmented by manually searching the references of key papers and related literature. The results were presented as a narrative review. RESULTS: Mitochondrial agents offer new horizons in mood disorder treatment. While some negative effects have been reported, most compounds are overall well tolerated and have generally benign side-effect profiles. CONCLUSIONS: The study of neuroinflammation, neurodegeneration, and mitochondrial function has contributed the understanding of bipolar disorder's pathophysiology. Agents targeting these pathways could be a potential therapeutic strategy. Future directions include identification of novel candidate mitochondrial modulators as well as rigorous and well-powered clinical trials.
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    The Post-Anaesthesia N-acetylcysteine Cognitive Evaluation (PANACEA) trial: study protocol for a randomised controlled trial
    Skvarc, DR ; Dean, OM ; Byrne, LK ; Gray, LJ ; Ives, K ; Lane, SE ; Lewis, M ; Osborne, C ; Page, R ; Stupart, D ; Turner, A ; Berk, M ; Marriott, AJ (BMC, 2016-08-09)
    BACKGROUND: Some degree of cognitive decline after surgery occurs in as many as one quarter of elderly surgical patients, and this decline is associated with increased morbidity and mortality. Cognition may be affected across a range of domains, including memory, psychomotor skills, and executive function. Whilst the exact mechanisms of cognitive change after surgery are not precisely known, oxidative stress and subsequent neuroinflammation have been implicated. N-acetylcysteine (NAC) acts via multiple interrelated mechanisms to influence oxidative homeostasis, neuronal transmission, and inflammation. NAC has been shown to reduce oxidative stress and inflammation in both human and animal models. There is clinical evidence to suggest that NAC may be beneficial in preventing the cognitive decline associated with both acute physiological insults and dementia-related disorders. To date, no trials have examined perioperative NAC as a potential moderator of postoperative cognitive changes in the noncardiac surgery setting. METHODS AND DESIGN: This is a single-centre, randomised, double-blind, placebo-controlled clinical trial, with a between-group, repeated-measures, longitudinal design. The study will recruit 370 noncardiac surgical patients at the University Hospital Geelong, aged 60 years or older. Participants are randomly assigned to receive either NAC or placebo (1:1 ratio), and groups are stratified by age and surgery type. Participants undergo a series of neuropsychological tests prior to surgery, 7 days, 3 months, and 12 months post surgery. It is hypothesised that the perioperative administration of NAC will reduce the degree of postoperative cognitive changes at early and long-term follow-up, as measured by changes on individual measures of the neurocognitive battery, when compared with placebo. Serum samples are taken on the day of surgery and on day 2 post surgery to quantitate any changes in levels of biomarkers of inflammation and oxidative stress. DISCUSSION: The PANACEA trial aims to examine the potential efficacy of perioperative NAC to reduce the severity of postoperative cognitive dysfunction in an elderly, noncardiac surgery population. This is an entirely novel approach to the prevention of postoperative cognitive dysfunction and will have high impact and translatable outcomes if NAC is found to be beneficial. TRIAL REGISTRATION: The PANACEA trial has been registered with the Therapeutic Goods Administration, and the Australian New Zealand Clinical Trials Registry: ACTRN12614000411640 ; registered on 15 April 2014.
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    The Glutathione System: A New Drug Target in Neuroimmune Disorders
    Morris, G ; Anderson, G ; Dean, O ; Berk, M ; Galecki, P ; Martin-Subero, M ; Maes, M (SPRINGER, 2014-12)
    Glutathione (GSH) has a crucial role in cellular signaling and antioxidant defenses either by reacting directly with reactive oxygen or nitrogen species or by acting as an essential cofactor for GSH S-transferases and glutathione peroxidases. GSH acting in concert with its dependent enzymes, known as the glutathione system, is responsible for the detoxification of reactive oxygen and nitrogen species (ROS/RNS) and electrophiles produced by xenobiotics. Adequate levels of GSH are essential for the optimal functioning of the immune system in general and T cell activation and differentiation in particular. GSH is a ubiquitous regulator of the cell cycle per se. GSH also has crucial functions in the brain as an antioxidant, neuromodulator, neurotransmitter, and enabler of neuron survival. Depletion of GSH leads to exacerbation of damage by oxidative and nitrosative stress; hypernitrosylation; increased levels of proinflammatory mediators and inflammatory potential; dysfunctions of intracellular signaling networks, e.g., p53, nuclear factor-κB, and Janus kinases; decreased cell proliferation and DNA synthesis; inactivation of complex I of the electron transport chain; activation of cytochrome c and the apoptotic machinery; blockade of the methionine cycle; and compromised epigenetic regulation of gene expression. As such, GSH depletion has marked consequences for the homeostatic control of the immune system, oxidative and nitrosative stress (O&NS) pathways, regulation of energy production, and mitochondrial survival as well. GSH depletion and concomitant increase in O&NS and mitochondrial dysfunctions play a role in the pathophysiology of diverse neuroimmune disorders, including depression, myalgic encephalomyelitis/chronic fatigue syndrome and Parkinson's disease, suggesting that depleted GSH is an integral part of these diseases. Therapeutical interventions that aim to increase GSH concentrations in vivo include N-acetyl cysteine; Nrf-2 activation via hyperbaric oxygen therapy; dimethyl fumarate; phytochemicals, including curcumin, resveratrol, and cinnamon; and folate supplementation.