Computerised cognitive–behavioural therapy (CCBT) is used for treating depression and provides a potentially useful alternative to therapist cognitive–behavioural therapy (CBT).

To systematically review the evidence for the effectiveness of CCBT for the treatment of mild to moderate depression.

Electronic databases were searched to identify randomised controlled trials. Selected studies were quality assessed and data extracted by two reviewers.

Four studies of three computer software packages met the inclusion criteria. Comparators were treatment as usual, using a depression education website and an attention placebo.

There is some evidence to support the effectiveness of CCBT for the treatment of depression. However, all studies were associated with considerable drop-out rates and little evidence was presented regarding participants' preferences and the acceptability of the therapy. More research is needed to determine the place of CCBT in the potential range of treatment options offered to individuals with depression.

Non-clinical psychotic symptoms appear common in children, but it is possible that a proportion of reported symptoms result from misinterpretation. There is a well-established association between pre-morbid low IQ score and schizophrenia. Psychosis-like symptoms in children may also be a risk factor for psychotic disorder but their relationship with IQ is unclear.

To investigate the prevalence, nature and frequency of psychosis-like symptoms in 12-year-old children and study their relationship with IQ.

Longitudinal study using the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort. A total of 6455 children completed screening questions for 12 psychotic symptoms followed by a semi-structured clinical assessment. IQ was assessed at 8 years of age using the Wechsler Intelligence Scale for Children (3rd UK edition).

The 6-month period prevalence for one or more symptoms was 13.7% (95% CI 12.8–14.5). After adjustment for confounding variables, there was a non-linear association between IQ score and psychosis-like symptoms, such that only those with below average IQ score had an increased risk of reporting such symptoms.

Non-clinical psychotic symptoms occur in a significant proportion of 12-year-olds. Symptoms are associated with low IQ and also less strongly with a high IQ score. The pattern of association with IQ differs from that observed in schizophrenia.

Promoting the mental health of people bereaved through suicide is a key aim of the National Suicide Prevention Strategy.

To evaluate the effects of interventions to support people bereaved through suicide.

We conducted a systematic review of data from controlled studies of interventions for people bereaved through suicide. Studies were identified using systematic searches, the methodological quality of included studies was assessed and narrative synthesis conducted.

Eight studies were identified. None was UK-based and all but one study had substantial methodological limitations. When compared with no intervention, there was evidence of some benefit from single studies of a cognitive–behavioural family intervention of four sessions with a psychiatric nurse; a psychologist-led 10-week bereavement group intervention for children; and 8-week group therapy for adults delivered by a mental health professional and volunteer. The findings from studies comparing two or more active interventions were more equivocal.

Although there is evidence of some benefit from interventions for people bereaved by suicide, this is not robust. Further methodologically sound evidence is required to confirm whether interventions are helpful and, if so, for whom.

It is unclear if research findings support clinical opinion that cannabis use leads to worse outcomes in people with psychosis, or whether this impression is confounded by other factors.

To systematically review the evidence pertaining to whether cannabis affects outcome of psychotic disorders.

We searched 10 relevant databases (to November 2006), reference lists of included studies and contacted experts. We included 13 longitudinal studies from 15 303 references. Data extraction and quality assessment were conducted independently and in duplicate.

Cannabis use was consistently associated with increased relapse and non-adherence. Associations with other outcome measures were more disparate. Few studies adjusted for baseline illness severity, and most made no adjustment for alcohol, or other potentially important confounders. Adjusting for even a few confounders often resulted in substantial attenuation of results.

Confidence that most associations reported were specifically due to cannabis is low. Despite clinical opinion, it remains important to establish whether cannabis is harmful, what outcomes are particularly susceptible, and how such effects are mediated. Studies to examine this further are eminently feasible.