The article by Smith et al (2016) provides a valuable summary on the usefulness and interpretation of systematic reviews. This commentary adds a discussion of confirmation bias and a summary of some of the most useful influential systematic reviews and meta-analyses in mental health.

Psychiatric expert witnesses instructed to undertake assessments of defendants charged with murder should be familiar with the partial defences of diminished responsibility and loss of control. The Coroners and Justice Act 2009 enacted major amendments to the partial defence of diminished responsibility and introduced a new defence of loss of control to replace the provocation partial defence. In this article, the changes to the law are described with particular focus on the implications for the psychiatric assessment.