There is urgent need to search for a dementia treatment that can delay its progression and reduce its financial and societal burden. Despite lacking evidence, there is a large number of commercial brain-training products on the market that claim they improve cognition. The Cochrane review under consideration looks at whether cognitive training maintains or improves cognition in those with mild to moderate dementia compared with control and alternative interventions. This commentary puts its findings into clinical perspective.

The COVID-19 pandemic is causing unprecedented rates of unemployment. Poorer mental health is a cause and a consequence of unemployment, and job seekers with poorer mental health remain unemployed for longer. The review in this month's Cochrane Corner aimed to evaluate the effects of health-improving interventions on job seeker's re-employment rates. This commentary critically evaluates the review and explores the relevance of its findings.

Overweight and obesity are growing health concerns globally. Technological advances drive interest in smartphone applications as possible health behaviour interventions to promote lifestyle change in these conditions. This article critically appraises a Cochrane Review of 18 studies (2703 participants) of smartphone app interventions for overweight or obesity in adolescents and adults and considers its relevance to clinical practice and research. The review's results suggest that there may be minimal benefit to the use of smartphone apps, but the evidence is very uncertain, lacking high-quality, replicable studies.

Music therapy has been a recognised form of therapy for mental illness for many years. This commentary on a Cochrane Review on music therapy for depression sheds light on the evidence. It aims to give further clinical context to the findings, to help guide practice and examine music therapy as an evidence-based practice. The review compares music therapy plus ‘treatment as usual’ (TAU) with TAU alone, music therapy with psychological therapy, and ‘active’ with ‘receptive’ music therapy (the two main types of music therapy). The review points to music therapy being beneficial for people with depression when combined with TAU (versus TAU alone) in the short term, as well as improving anxiety and functioning. We need more evidence looking at longer-term outcomes, comparing music therapy with psychological therapies and comparing different forms of music therapy.

Approximately 25% of people will be affected by a mental disorder at some stage in their life. Despite the prevalence and negative impacts of mental disorders, many people are not diagnosed or do not receive adequate treatment. Therefore primary healthcare has been identified as essential to improving the delivery of mental healthcare. Consultation liaison is a model of mental healthcare where the primary care provider maintains the central role in the delivery of mental healthcare, with a mental health specialist providing consultative support. Consultation liaison has the potential to enhance the delivery of mental healthcare in the primary care setting and, in turn, improve outcomes for people with a mental disorder.

Individuals with severe mental illness have increased rates of physical health problems and reduced life expectancy. As a vulnerable population, they have been identified as needing increased physical health monitoring and treatment. The first of two Cochrane reviews considered here assessed the evidence for the benefit of monitoring but found no studies that could be included. The second reviewed the evidence for provision of general physical healthcare advice. Although the results were suggestive of benefit, the evidence, where available, was of poor quality. These reviews highlight an important area for future research to evaluate the relative health and cost benefits of different types of intervention.

‘Collaborative care’ (involving a case manager) and ‘primary care liaison’ or ‘consultation liaison’ (with no case manager) are models of liaison psychiatry in primary care. Here, I briefly consider the evidence for collaborative care, discuss Gillies et al 's Cochrane review on consultation liaison, and suggest avenues for future study and development of liaison psychiatry in primary care.

Major depressive disorder in children and adolescents is common and associated with significant morbidity and mortality. This 2012 meta-analysis by Hetrick et al shows statistically significant, but small, improvements in depressive symptom scores and probability of remission with second-generation antidepressants (SGAs) compared with placebo. SGAs lead to a small, but significant, increase in risk of suicidal thoughts/attempts compared with placebo. Patients included in the primary studies had milder depression, less psychiatric comorbidity and less suicidality than those normally seen in clinical practice in the UK's National Health Service. However, primary studies had significant methodological shortcomings. Therefore, caution is needed when trying to generalise results to clinical practice.

Depression has a large socioeconomic burden, affecting an estimated 280 million people worldwide. Up to 55% remain symptomatic following pharmacological and psychological treatment and may be classified as having treatment-resistant depression. This commentary assesses two treatment options for this group – electroconvulsive therapy (ECT) and a novel approach, magnetic seizure therapy (MST) – with reference to a Cochrane Review comparing the two. The Cochrane analysis showed no clear benefit for MST, but the evidence is currently insufficient to draw firm conclusions.

Family therapy is recommended by the National Institute for Health and Care Excellence (NICE) for the management of anorexia nervosa in children and young people, but there is limited evidence to back this recommendation. The Cochrane Review under consideration evaluates the efficacy of different family therapy approaches compared with other treatments for anorexia nervosa, and this commentary puts the findings into clinical perspective.

This critical appraisal of a Cochrane Review assesses the efficacy of ketamine for treating unipolar major depressive disorder. The review included 31 randomised controlled trials involving ketamine. Results indicate that intravenous (i.v.) ketamine significantly improves antidepressant response compared with i.v. saline and, to a lesser extent, i.v. midazolam within 24–72 h. However, the evidence is constrained by performance bias owing to masking (‘blinding’) concerns and study heterogeneity, necessitating further robust research to confirm ketamine's clinical potential.