Prior trials suggest that intravenous racemic ketamine is a highly effective for treatment-resistant depression (TRD), but phase 3 trials of racemic ketamine are needed.

To assess the acute efficacy and safety of a 4-week course of subcutaneous racemic ketamine in participants with TRD. Trial registration: ACTRN12616001096448 at www.anzctr.org.au.

This phase 3, double-blind, randomised, active-controlled multicentre trial was conducted at seven mood disorders centres in Australia and New Zealand. Participants received twice-weekly subcutaneous racemic ketamine or midazolam for 4 weeks. Initially, the trial tested fixed-dose ketamine 0.5 mg/kg versus midazolam 0.025 mg/kg (cohort 1). Dosing was revised, after a Data Safety Monitoring Board recommendation, to flexible-dose ketamine 0.5–0.9 mg/kg or midazolam 0.025–0.045 mg/kg, with response-guided dosing increments (cohort 2). The primary outcome was remission (Montgomery-Åsberg Rating Scale for Depression score ≤10) at the end of week 4.

The final analysis (those who received at least one treatment) comprised 68 in cohort 1 (fixed-dose), 106 in cohort 2 (flexible-dose). Ketamine was more efficacious than midazolam in cohort 2 (remission rate 19.6% v. 2.0%; OR = 12.1, 95% CI 2.1–69.2, P = 0.005), but not different in cohort 1 (remission rate 6.3% v. 8.8%; OR = 1.3, 95% CI 0.2–8.2, P = 0.76). Ketamine was well tolerated. Acute adverse effects (psychotomimetic, blood pressure increases) resolved within 2 h.

Adequately dosed subcutaneous racemic ketamine was efficacious and safe in treating TRD over a 4-week treatment period. The subcutaneous route is practical and feasible.

There is currently little consensus as to how burnout is best defined and measured, and whether the syndrome should be afforded clinical status. The latter issue would be advanced by determining whether burnout is a singular dimensional construct varying only by severity (and with some level of severity perhaps indicating clinical status), or whether a categorical model is superior, presumably reflecting differing ‘sub-clinical’ versus ‘clinical’ or ‘burning out’ vs ‘burnt out’ sub-groups. This study sought to determine whether self-diagnosed burnout was best modelled dimensionally or categorically.

We recently developed a new measure of burnout which includes symptoms of exhaustion, cognitive impairment, social withdrawal, insularity, and other psychological symptoms. Mixture modelling was utilised to determine if scores from 622 participants on the measure were best modelled dimensionally or categorically.

A categorical model was supported, with the suggestion of a sub-syndromal class and, after excluding such putative members of that class, two other classes. Analyses indicated that the latter bimodal pattern was not likely related to current working status or differences in depression symptomatology between participants, but reflected subsets of participants with and without a previous diagnosis of a mental health condition.

Findings indicated that sub-categories of self-identified burnout experienced by the lay population may exist. A previous diagnosis of a mental illness from a mental health professional, and therefore potentially a psychological vulnerability factor, was the most likely determinant of the bimodal data, a finding which has theoretical implications relating to how best to model burnout.

Reduction of the pulse width has been reported to improve ECT outcomes with unilateral ECT (similar efficacy, fewer cognitive side effects), but has been minimally studied for bitemporal ECT. The only study comparing brief and ultrabrief pulse bitemporal ECT found reduced efficacy for bitemporal ultrabrief compared to bitemporal brief pulse stimulation. This randomised controlled trial (RCT) aimed to test if ultrabrief pulse bitemporal ECT results in fewer cognitive side effects than brief pulse bitemporal ECT, when given at doses adjusted with the aim of achieving comparable efficacy.

Thirty-six participants were randomly assigned to receive ultrabrief (at 3 times seizure threshold) or brief (at 1.5 times seizure threshold) pulse bitemporal ECT given 3 times a week in a double-blind, controlled proof-of-concept trial. Blinded raters assessed mood and cognitive functioning over the ECT course.

Efficacy and cognitive outcomes did not differ significantly between the two treatment groups over the ECT course. The ultrabrief pulse group performed better on a test of visual memory assessed acutely after an ECT treatment.

This study suggests there may be a small cognitive advantage in giving bitemporal ECT with an ultrabrief pulse when dosage is increased to match the efficacy of brief pulse bitemporal ECT, but the study was underpowered to fully examine this issue.

Clinical Trials Registration: www.clinicaltrials.gov, NCT00870805.

The mental health and social functioning of millions of forcibly displaced individuals worldwide represents a key public health priority for host governments. This is the first longitudinal study with a representative sample to examine the impact of interpersonal trust and psychological symptoms on community engagement in refugees.

Participants were 1894 resettled refugees, assessed within 6 months of receiving a permanent visa in Australia, and again 2–3 years later. Variables measured included post-traumatic stress disorder symptoms, depression/anxiety symptoms, interpersonal trust and engagement with refugees’ own and other communities.

A multilevel path analysis was conducted, with the final model evidencing good fit (Comparative Fit Index = 0.97, Tucker–Lewis Index = 0.89, Root Mean Square Error of Approximation = 0.05, Standardized Root-Mean-Square-Residual = 0.05). Findings revealed that high levels of depression symptoms were associated with lower subsequent engagement with refugees’ own communities. In contrast, low levels of interpersonal trust were associated with lower engagement with the host community over the same timeframe.

Findings point to differential pathways to social engagement in the medium-term post-resettlement. Results indicate that depression symptoms are linked to reduced engagement with one's own community, while interpersonal trust is implicated in engagement with the broader community in the host country. These findings have potentially important implications for policy and clinical practice, suggesting that clinical and support services should target psychological symptoms and interpersonal processes when fostering positive adaptation in resettled refugees.

Identifying clinical features that predict conversion to bipolar disorder (BD) in those at high familial risk (HR) would assist in identifying a more focused population for early intervention.

In total 287 participants aged 12–30 (163 HR with a first-degree relative with BD and 124 controls (CONs)) were followed annually for a median of 5 years. We used the baseline presence of DSM-IV depressive, anxiety, behavioural and substance use disorders, as well as a constellation of specific depressive symptoms (as identified by the Probabilistic Approach to Bipolar Depression) to predict the subsequent development of hypo/manic episodes.

At baseline, HR participants were significantly more likely to report ⩾4 Probabilistic features (40.4%) when depressed than CONs (6.7%; p < .05). Nineteen HR subjects later developed either threshold (n = 8; 4.9%) or subthreshold (n = 11; 6.7%) hypo/mania. The presence of ⩾4 Probabilistic features was associated with a seven-fold increase in the risk of ‘conversion’ to threshold BD (hazard ratio = 6.9, p < .05) above and beyond the fourteen-fold increase in risk related to major depressive episodes (MDEs) per se (hazard ratio = 13.9, p < .05). Individual depressive features predicting conversion were psychomotor retardation and ⩾5 MDEs. Behavioural disorders only predicted conversion to subthreshold BD (hazard ratio = 5.23, p < .01), while anxiety and substance disorders did not predict either threshold or subthreshold hypo/mania.

This study suggests that specific depressive characteristics substantially increase the risk of young people at familial risk of BD going on to develop future hypo/manic episodes and may identify a more targeted HR population for the development of early intervention programs.