Many people who have self-harmed prefer informal sources of support or support from those with lived experience. However, little is known about whether peer support improves outcomes for people who have self-harmed or about the risks of peer support interventions in non-clinical settings.

The aims of this review were to examine the effectiveness, acceptability and potential risks of peer support for self-harm, and how these risks might be mitigated.

We searched bibliographic databases and grey literature for papers published since 2000. We included peer support for self-harm that occurred in voluntary-sector organisations providing one-to-one or group support, or via moderated online peer support forums.

Eight of the ten papers included focused on peer support that was delivered through online media. No study compared peer support with other treatments or a control group, so limited conclusions could be made about its effectiveness. Peer support for self-harm was found to be acceptable and was viewed as having a range of benefits including a sense of community, empowerment, and access to information and support. The most commonly perceived risk associated with peer support was the potential for triggering self-harm.

Our findings highlighted a range of benefits of being part of a group with very specific shared experiences. Mitigations for potential risks include organisations using professional facilitators for groups, trigger warnings for online forums, and providing regular supervision and training so that peers are prepared and feel confident to support vulnerable people while maintaining their own emotional health.

Children and adolescents display different symptoms of post-traumatic stress disorder (PTSD) than adults. Whilst evidence for the effectiveness of psychological interventions has been synthesised for adults, this is not directly applicable to younger people. Therefore, this systematic review and meta-analysis synthesised studies investigating the effectiveness of psychological interventions for PTSD in children, adolescents and young adults. It provides an update to previous reviews investigating interventions in children and adolescents, whilst investigating young adults for the first time.

We searched published and grey literature to obtain randomised control trials assessing psychological interventions for PTSD in young people published between 2011 and 2019. Quality of studies was assessed using the Cochrane Risk of Bias tool. Data were analysed using univariate random-effects meta-analysis.

From 15 373 records, 27 met criteria for inclusion, and 16 were eligible for meta-analysis. There was a medium pooled effect size for all psychological interventions (d = −0.44, 95% CI −0.68 to −0.20), as well as for Trauma-Focused Cognitive Behavioural Therapy (TF-CBT) and Eye Movement Desensitisation and Reprocessing (EMDR) (d = −0.30, 95% CI −0.58 to −0.02); d = −0.46, 95% CI −0.81 to −0.12).

Some, but not all, psychological interventions commonly used to treat PTSD in adults were effective in children, adolescents and young adults. Interventions specifically adapted for younger people were also effective. Our results support the National Institute for Health and Care Excellence guidelines which suggest children and adolescents be offered TF-CBT as a first-line treatment because of a larger evidence base, despite EMDR being more effective.