Faculty Bibliography

Given the high prevalence of treatment-resistant depression and the long delays in finding effective treatments via trial and error, valid biomarkers of treatment outcome with the ability to guide treatment selection represent one of the most important unmet needs in mood disorders. A large body of research has investigated, for this purpose, biomarkers derived from electroencephalography (EEG), using resting state EEG or evoked potentials. Most studies have focused on specific EEG features (or combinations thereof), whereas more recently machine-learning approaches have been used to define the EEG features with the best predictive abilities without a priori hypotheses. While reviewing these different approaches, we have focused on the predictor characteristics and the quality of the supporting evidence.

We examined the use of near-infrared and red radiation (photobiomodulation, PBM) for treating major depressive disorder (MDD). While still experimental, preliminary data on the use of PBM for brain disorders are promising. PBM is low-cost with potential for wide dissemination; further research on PBM is sorely needed. We found clinical and preclinical studies via PubMed search (2015), using the following keywords: "near-infrared radiation," "NIR," "low-level light therapy," "low-level laser therapy," or "LLLT" plus "depression." We chose clinically focused studies and excluded studies involving near-infrared spectroscopy. In addition, we used PubMed to find articles that examine the link between PBM and relevant biological processes including metabolism, inflammation, oxidative stress, and neurogenesis. Studies suggest the processes aforementioned are potentially effective targets for PBM to treat depression. There is also clinical preliminary evidence suggesting the efficacy of PBM in treating MDD, and comorbid anxiety disorders, suicidal ideation, and traumatic brain injury. Based on the data collected to date, PBM appears to be a promising treatment for depression that is safe and well-tolerated. However, large randomized controlled trials are still needed to establish the safety and effectiveness of this new treatment for MDD.

Approximately one-third of patients with major depressive disorder (MDD) do not respond to existing antidepressants, and those who do generally take weeks to months to achieve a significant effect. There is a clear unmet need for rapidly acting and more efficacious treatments. We will review recent developments in the study of ketamine, an old anaesthetic agent which has shown significant promise as a rapidly acting antidepressant in treatment-resistant patients with unipolar MDD, focusing on clinically important aspects such as dose, route of administration and duration of effect. Additional evidence suggests ketamine may be efficacious in patients with bipolar depression, post-traumatic stress disorder and acute suicidal ideation. We then discuss the safety of ketamine, in which most neuropsychiatric, neurocognitive and cardiovascular disturbances are short lasting; however, the long-term effects of ketamine are still unclear. We finally conclude with important information about ketamine for primary and secondary physicians as evidence continues to emerge for its potential use in clinical settings, underscoring the need for further investigation of its effects.

PURPOSE: This study aims to determine whether Psychiatric Electroencephalography Evaluation Registry (PEER) Interactive (an objective, adjunctive tool based on a comparison of a quantitative electroencephalogram to an existing registry of patient outcomes) is more effective than the current standard of care in treatment of subjects suffering from depression. PATIENTS AND METHODS: This is an interim report of an ongoing, 2-year prospective, randomized, double blind, controlled study to evaluate PEER Interactive in guiding medication selection in subjects with a primary diagnosis of depression vs standard treatment. Subjects in treatment at two military hospitals were blinded as to study group assignment and their self-report symptom ratings were also blinded. Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR16) depression scores were the primary efficacy endpoint. One hundred and fifty subjects received a quantitative electroencephalography exam and were randomized to either treatment as usual or PEER-informed pharmacotherapy. Subjects in the control group were treated according to Veterans Administration/Department of Defense Guidelines, the current standard of care. In the experimental group, the attending physician received a PEER report ranking the subject's likely clinical response to on-label medications. RESULTS: In this post hoc interim analysis subjects were separated into Report Followed and Report Not Followed groups - based on the concordance between their subsequent treatment and PEER medication guidance. We thus evaluated the predictive validity of PEER recommendations. We found significantly greater improvements in depression scores (QIDS-SR16 P<0.03), reduction in suicidal ideation (Concise Health Risk Tracking Scale-SR7 P<0.002), and post-traumatic stress disorder (PTSD) score improvement (PTSD Checklist Military/Civilian P<0.04) for subjects treated with PEER-recommended medications compared to those who did not follow PEER recommendations. CONCLUSION: This interim analysis suggests that an objective tool such as PEER Interactive can help improve medication selection. Consistent with results of earlier studies, it supports the hypothesis that PEER-guided treatment offers distinct advantages over the current standard of care.

BACKGROUND: Suicide is a devastating public health problem and very few biological treatments have been found to be effective for quickly reducing the intensity of suicidal ideation (SI). We have previously shown that a single dose of ketamine, a glutamate N-methyl-d-aspartate (NMDA) receptor antagonist, is associated with a rapid reduction in depressive symptom severity and SI in patients with treatment-resistant depression. METHOD: We conducted a randomized, controlled trial of ketamine in patients with mood and anxiety spectrum disorders who presented with clinically significant SI (n = 24). Patients received a single infusion of ketamine or midazolam (as an active placebo) in addition to standard of care. SI measured using the Beck Scale for Suicidal Ideation (BSI) 24 h post-treatment represented the primary outcome. Secondary outcomes included the Montgomery-Asberg Depression Rating Scale--Suicidal Ideation (MADRS-SI) score at 24 h and additional measures beyond the 24-h time-point. RESULTS: The intervention was well tolerated and no dropouts occurred during the primary 7-day assessment period. BSI score was not different between the treatment groups at 24 h (p = 0.32); however, a significant difference emerged at 48 h (p = 0.047). MADRS-SI score was lower in the ketamine group compared to midazolam group at 24 h (p = 0.05). The treatment effect was no longer significant at the end of the 7-day assessment period. CONCLUSIONS: The current findings provide initial support for the safety and tolerability of ketamine as an intervention for SI in patients who are at elevated risk for suicidal behavior. Larger, well-powered studies are warranted.

OBJECTIVE: People with bipolar disorder are at high risk of suicide, but no clinically useful scale has been validated in this population. The aim of this study was to evaluate the psychometric properties in bipolar disorder of the 7- and 12-item versions of the Concise Health Risk Tracking Self-Report (CHRT-SR), a scale measuring suicidal ideation, suicidal behavior, and associated symptoms. METHODS: The CHRT was administered to 283 symptomatic outpatients with bipolar I or II disorder who were randomized to receive lithium plus optimized personalized treatment (OPT), or OPT without lithium in a six month longitudinal comparative effectiveness trial. Participants were assessed using structured diagnostic interviews, clinician-rated assessments, and self-report questionnaires. RESULTS: The internal consistency (Cronbach alpha) was 0.80 for the 7-item CHRT-SR and 0.90 for the 12-item CHRT-SR with a consistent factor structure, and three independent factors (current suicidal thoughts and plans, hopelessness, and perceived lack of social support) for the 7-item version. CHRT-SR scores are correlated with measures of depression, functioning, and quality of life, but not with mania scores. CONCLUSIONS: The 7- and 12-item CHRT-SR both had excellent psychometric properties in a sample of symptomatic subjects with bipolar disorder. The scale is highly correlated with depression, functioning, and quality of life, but not with mania. Future research is needed to determine whether the CHRT-SR will be able to predict suicide attempts in clinical practice.

BACKGROUND: Anhedonia represents a core symptom of major depression and may be a potential marker for melancholia. However, current understanding of this construct in depressive sub-types is limited. METHOD: Participants were recruited from the Black Dog Institute (Sydney) and Massachusetts General Hospital (Boston). Diagnostic groups were derived on the basis of agreement between clinician and DSM-IV diagnosis from structured interviews. Currently depressed unipolar melancholic, non-melancholic and healthy control participants were administered a probabilistic reward task (PRT) to assess a behavioural correlate of anhedonia-blunted reward-based learning. Self-reported measures of anhedonia, approach and avoidance motivation were completed by the Sydney sample. RESULTS: Relative to healthy controls and non-melancholic participants, melancholic depressed participants had reduced response bias, highlighting blunted reward learning. Moreover, although non-melancholic participants were characterized by a delayed response bias, melancholic depressed participants failed to develop a bias throughout blocks. Response bias showed no associations with self-report measures of hedonic tone in depressed participants. Positive associations were observed between response bias, approach and avoidance motivation in non-melancholic participants only. LIMITATIONS: Possible medication, fatigue and anxiety effects were not controlled; small sample sizes; inclusion criteria may have excluded those with severe melancholia and led to underestimation of group differences. CONCLUSIONS: Melancholia is characterised by a reduced ability to modulate behaviour as a function of reward, and the motivational salience of rewarding stimuli may differ across depressive sub-types. Results support the view that melancholia is a distinct sub-type. Further exploration of reward system functioning in depressive sub-types is warranted.