Effects of cognitive behavioral therapy for insomnia on executive functions: A randomized active-controlled trial.
Executive functions (EFs) are a set of cognitive control processes involved in the regulation of basic psychological functions such as attention, memory and emotion. Meta-analytic evidence supports the presence of impaired EFs in individuals with insomnia disorder, the most common sleep disorder affecting one third of the general population and associated with mental and physical illness. The effects of standard treatment for insomnia (i.e., cognitive behavior therapy for insomnia, CBT-I ) on EFs, however, are yet to be clear. In fact, only four studies investigated the impact of CBT-I on EFs with inconsistent results. The aim of this study is to investigate the effectiveness of CBT-I on EFs using a randomized active-controlled trial design. Thirty patients with a diagnosis of insomnia disorder will be randomly allocated either to the experimental or the control group. The experimental group will receive four weekly sessions of CBT-I in a face-to-face individual setting. Treatment will include the techniques of stimulus control, sleep compression, cognitive restructuring, cognitive control, sleep hygiene and relaxation. Participants in the control group will receive the same CBT-I techniques but in a self-help format (booklets plus weekly calls of a clinical psychologist). EFs will be measured at baseline, after treatment and after two months of follow up using the Task Switching paradigm which assesses the EFs of response inhibition and cognitive flexibility. Results will be analyzed through a 3x2 mixed design factorial ANOVA Time (baseline vs post-test vs follow up) x Group (Treatment vs Control) on the two indices of the Task Switching performance (Backward Inhibition and Switch Cost, measures of response inhibition and cognitive flexibility, respectively). This study will advance the knowledge on the effectiveness of CBT-I on daytime functioning of individuals with insomnia.