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

Participants were 411 adults (Mage = 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.