Let's talk about sleep: a systematic review of psychological interventions to improve sleep in college students.

Sleep problems are a common occurrence in college students. Insomnia, nightmares and impaired sleep quality lead to several mental health issues, as well as impaired academic performance. Although different sleep programmes exist, a systematic overview comparing their effectiveness is still missing. This systematic review aims to provide an overview of psychological interventions to improve sleep in college students. Seven databases were searched from November to December 2016 (MEDLINE, EMBASE, PsycINFO, Cinahl, Cochrane Library, PubMed, OpenSigle). The search string included search terms from three different topics: sleep, intervention and college students. Outcome measures included subjective as well as objective measures and focused on sleep, sleep-related and mental health variables. Twenty-seven studies met the inclusion criteria. They were assigned to four intervention categories: (1) sleep hygiene, (2) cognitive-behavioural therapy (CBT), (3) relaxation, mindfulness and hypnotherapy and (4) other psychotherapeutic interventions. Fifteen studies were randomized controlled trials. While sleep hygiene interventions provided small to medium effects, the CBTs showed large effects. The variability of the effect sizes was especially large in the relaxation category, ranging from very small to very large effect sizes. Other psychotherapeutic interventions showed medium effects. CBT approaches provided the best effects for the improvement of different sleep variables in college students. Five studies included insomnia patients. The other three intervention categories also showed promising results with overall medium effects. In the future, CBT should be combined with relaxation techniques, mindfulness and hypnotherapy. Furthermore, the interventions should broaden their target group and include more sleep disorders.