Title: Cognitive Behavioural Therapy for Chronic Insomnia: A Systematic Review
Objectives: This work intends to determinate the efficacy and impact of CBT-I on sleep and day-time consequences of insomnia.
Background and aims: Insomnia is frequently reported by patients in clinical practice. Prevalence can range between 10% and 40% in the case of intermittent insomnia, being even more common among patients with psychiatric disorders (50-80% have insomnia at some point in the development of their disorder). Considering the high prevalence of sleep disorders and comorbidity with various psychiatric diseases, effective treatment of insomnia is a relevant topic in clinical practice. Because psychological approaches are likely to produce sustained benefits, without the risk for tolerance or adverse effects associated with pharmacologic approaches, cognitive behavioural therapy for insomnia (CBT-i) is now commonly recommended as first-line treatment for chronic insomnia in many international guidelines (e.g. National Institute of Health Consensus-NICE and Statement and Brit¬ish Association of Psychopharmacology).
Materials and methods: A comprehensive search was conducted on the principal medical databases including MEDLINE, Cochrane Library and PubMed. Search terms covered 2 concepts: (1) [Cognitive behaviour therapy for insomnia] AND (2) [insomnia OR sleep disorders].
 Results: Several trials showed that CBT-I improved insomnia severity, sleep efficiency, subjective sleep quality, wake after sleep onset, sleep onset latency, total sleep time, and number of nocturnal awakenings at post-treatment. The effects of CBT-I over the internet (e CBT-I) were comparable to those found to CBT-I. 
 Conclusions:
CBT-I appears to be effective and can be considered a viable option in the treatment of insomnia that should be offered to all patients as first-line treatment

Effectiveness of Cognitive Behavioral Therapy for Insomnia: a Systematic Review