A Cochrane review has compared short-stay hospital admission with long-stay/standard admission of patients with severe mental illness for a number of outcomes in a total 2030 participants from 6 randomised trials. It reached the conclusion, supported by limited evidence, that short admissions in mental health units do not increase the risk of death, readmission or worsening of mental state, and pose less risk of delayed discharge and patient's unemployment. This commentary examines the available evidence from previous studies and discusses its relevance to current practice.

Considering the ample evidence of involvement of the glutamate system in the pathophysiology of depression, pre-clinical and clinical studies have been conducted to assess the antidepressant efficacy of glutamate inhibition, and glutamate receptor modulators in particular. This review focuses on the use of glutamate receptor modulators in unipolar depression.

There is emerging evidence that glutamatergic system dysfunction might play an important role in the pathophysiology of bipolar depression. This review focuses on the use of glutamate receptor modulators for depression in bipolar disorder.

Glutamate receptor modulators, including ketamine, are possible candidates for new antidepressants with a novel mode of action. The pair of reviews discussed in this month's Round the Corner considered their use in treating unipolar major depression and bipolar depression. Promising results were seen for ketamine, but further studies are needed, in particular to investigate whether the benefits are sustained or can be extended by repeated or adjunctive treatment, whether ketamine is effective in treatment resistance, whether other modes of administration are as effective as the intravenous route and the long-term adverse effects of use.

Parent–infant psychotherapy (PIP) is a psychoanalytic intervention that aims to improve parental and infant mental health. There is uncertainty about the clinical effectiveness of this intervention, particularly in comparison with other interventions. Based on a limited number of trials, this month's Cochrane Corner review aimed to summarise the best evidence available. Although the review found some tentative support for PIP in relation to attachment outcomes, overall the evidence was of low quality and PIP was not found to be more effective than treatment as usual or other interventions. This commentary contextualises and summarises the findings, and considers their implications for researchers and clinicians.

Drug treatments are commonly used for sleep disturbance in Alzheimer's disease, although none have a specific licence for this indication. This month's Cochrane review assessed the available evidence of benefit or harm in the use of these medications. The review identified two studies of melatonin, which did not show significant improvement in sleep over placebo. One study of trazodone suggested a beneficial effect on sleep, but its small sample size limits the generalisability of the results. Larger studies are needed, with careful assessment of the evidence for possible improvements in sleep but also of important side-effects such as falls and increased confusion.

Formal communication skills training is the norm at UK medical schools, and evidence is mounting that it is effective in a number of domains, including patient satisfaction and shared decision-making, leading to improved treatment adherence. However, applying these models in mental health settings is challenging, despite the fact that positive therapeutic relationships and an ability to actively manage consultations are the cornerstone of psychiatric practice. Communication skills training is still too often regarded as better suited to physical health consultations than more complex psychiatric interviews. Here, it is considered why this might be, with reference to the one eligible randomised controlled trial identified in this systematic literature review.

A ‘control’ provides a point of clinical comparison for a new intervention, allowing researchers and clinicians to draw more confident conclusions about the effectiveness or potential harm of a given, often novel, therapy. Although this aspect of a trial's design provides the basis from which interventional impact is measured, it is often less closely examined. This commentary appraises a Cochrane Review that compares various controls in common use in modern psychiatric research and aims to characterise their effects on the outcomes of that research.

Determining the optimum next-step treatment for the numerous patients with depression who do not adequately respond to an initial trial of medication remains a source of uncertainty in clinical practice. Although a number of psychological treatments are known to be effective for depression, their relative merits in the treatment-resistant group have not been ascertained. The Cochrane Collaboration has recently published a meta-analysis of the evidence available for the use of various psychotherapies as an adjunct to antidepressants compared with antidepressants alone in treatment-resistant depression. This article provides a commentary and appraisal of the clinical utility of these findings.

Diabetes and depression have a bidirectional relationship, but some antidepressants (such as the tricyclics) may have detrimental effects in diabetes that are exacerbated by behavioural changes associated with depression. This month's Cochrane Review evaluated the efficacy of psychological and pharmacological treatments of comorbid depression in diabetes and found that such interventions have a moderate and clinically significant effect on depression outcomes in people with diabetes. However, conclusions were limited by significant heterogeneity within examined populations and interventions, and significant risk of bias within trials. This commentary critically appraises the review and aims to contextualise its findings.

Although antipsychotic medication remains the mainstay of treatment for schizophrenia, medications alone are not always successful. Cognitive–behavioural therapy (CBT) is recommended as an adjunct to pharmacological treatment. The Cochrane review under consideration evaluates the effects of offering CBT as an add-on to standard care compared with standard care alone, and this commentary puts those findings into their clinical context.