Acceptance and Commitment Therapy for Insomnia (ACT-I)

Insomnia is a frequent complaint and is associated with impairments in physical and psychological health. Although Cognitive-Behavioral Therapy (CBT) demonstrates effective results for insomnia, there are those who do not respond to this type of intervention or present difficulties in adherence. Acceptance and Commitment Therapy (ACT) presents itself as a potentially useful intervention for the treatment of insomnia, for which, instead of focusing on controlling the symptoms, the respective approach focuses on accepting the feelings and thoughts associated, through value-based actions. The aim of this study is to evaluate the effectiveness of ACT for chronic insomnia in adults. Participants will be 150 adults aged between 18 and 59 years, diagnosed with chronic insomnia who will be randomly assigned to the ACT, CBT and wait list (WL) groups. For both groups (ACT and CBT), the intervention will be performed in six group and weekly sessions. Assessments of sleep patterns, insomnia, depression, anxiety, psychological flexibility, acceptance of sleep, beliefs about sleep, personality traits will be performed in the pre-treatment, post-treatment and six-month follow-up. After the intervention is completed, participants will respond to an inventory of compliance and satisfaction. Treatment effects will assessed using the fixed effects of group variables (ACT vs. CBT-I and ACT vs. waitlist) and their interaction with time (pre-test vs. post-test and pretest vs. six-month follow-up). We will estimated pairwise contrasts to examine changes across time within groups. Variables will analyzed using generalized mixed models (GMM).

ACT-I treatment group: Participants diagnosed with chronic insomnia will receive group treatment. The six sessions will be aimed at psychoeducation about sleep added to the therapeutic processes of acceptance, mindfulness, availability, values, defusion and commitment, used in ACT.

Active control group CBT-I: Participants diagnosed with chronic insomnia will receive treatment in a group. The six sessions will be aimed at cognitive-behavioral components, such as education and sleep hygiene, stimulus control, sleep restriction and demystification / restructuring of belief beliefs.

Change in the total score for the anxiety variable (HADAS-A) and total score for the depression variable (HADAS-D)

Inclusion Criteria: Clinical diagnosis of chronic insomnia Exclusion Criteria: Neurological degenerative disease Psychotic disorder sleep apnea, restless legs or periodic limb movements during sleep, or a circadian-based sleep disorder (e.g., delayed or advanced sleep phase syndrome) cognitive impairments unavailability in attending the sessions.