Sleep hygiene and sleep control mediate the relationship between cognitive fusion and insomnia severity

OBJECTIVES: Insomnia is associated with mental ill health, worry and rumination-the two latter contribute to pre-sleep cognitive arousal. These variables also associate with psychological inflexibility, including cognitive fusion (CF), a literal attachment to unhelpful thoughts, patterns and rules. Good sleepers generally have low CF, good sleep hygiene and a belief in sleep control, but individuals high in CF may have unhelpful beliefs about sleep hygiene and sleep control. METHODS: We investigated associations between CF, sleep hygiene and sleep control, hypothesizing that each would contribute significant variance to insomnia and mediate the relationship between CF and insomnia. RESULTS: = 45.9 years, SD = 15.6) completing an online survey including demographics, and questionnaires about insomnia (ISI), CF (CFQ), sleep hygiene (SHS) and sleep control (BRISC). Hierarchical regression accounted for 34% of variance in insomnia (p < .001), showing that after controlling for demographic variables, CF, sleep hygiene and sleep control each accounted for significant variance in insomnia, with sleep control the strongest predictor (β = -.304). Parallel mediation modelling accounting for 22.2% of variance in insomnia (p < .001) showed both sleep hygiene and sleep control partially mediated the CF and insomnia relationship. CONCLUSIONS: Our study shows for the first time that CF, sleep hygiene and sleep control beliefs are inter-related in their impact on insomnia. As CF is a core component of psychological inflexibility, ACT plus behaviour therapy (ACT-I) may be a more suitable insomnia intervention than CBT plus behaviour therapy (CBT-I) for some people.