Insomnia : a problem-solving approach to treatment and an exploration of worry

Abstract

Insomnia is a debilitating sleep disorder involving dissatisfaction with the quality, timing, or duration of sleep. A review of the literature reveals that insomnia results in impaired daytime functioning and quality of life, and it can worsen the course of common co-existing medical and mental illnesses. Insomnia is thought to manifest as the result of a complex interaction of cognitive, behavioural and physiological processes including the engagement in excessive worry, sleep-interfering habits, and physical and psychological reactivity to stress. Attempts to treat insomnia using pharmacotherapy have generally been effective only in the short-term, whilst psychological and behavioural approaches show promise as lasting treatments. Whilst being the most popular and widely recommended evidenced-based multi-component treatment for insomnia to date, cognitive behavioural therapy for insomnia (CBT-I) has recognised limitations to its effectiveness. Little is known about the mechanisms of insomnia, both in its maintenance and recovery. There are a range of possible contributors to the sleep disorder that existing treatments address only in a limited way, such as excessive worry, personal coping, self-efficacy, and problem-solving ability. The first study described in this thesis aimed to explore the nature of worry in adults with insomnia to inform potential treatment advances in the field. Specifically, worry process and content were explored, along with their relationship to problem-solving domains, via a cross-sectional assessment. Adults (18 - 60 years) with and without insomnia completed worry questionnaires, a problem-solving inventory, and a 'thought diary'. Compared to good sleepers, poor sleepers reported significantly higher levels of worry, negative problem orientation and avoidance style. Problem-solving orientation significantly correlated with worry in poor sleepers and problem-solving process thoughts predominated for both groups. Regardless of sleep status and time of day, participants identified similar primary concerns in the thought diary. This implies that insomnia may be represented by an amplified manifestation of day-to-day worries, combined with concerns about sleep and health, potentially reflecting a process of dysfunctional problem-solving. This supports the testing of interventions targeted at enhancing problem orientation and skills, and reducing the tendency to engage in dysfunctional worry. The second study subsequently tested the efficacy of Problem-Solving Therapy (PST) for the treatment of insomnia in comparison to the standard Cognitive Therapy (CT) approach. Both treatments were coupled with initial sleep education, relaxation and a behavioural element, as neither PST nor CT have demonstrated efficacy as independent therapies. This second study further represents a preliminary exploration into the mechanisms that influence treatment response to PST and CT. It consists of a six-week randomised controlled clinical treatment trial involving forty-seven adults (18 - 60 years) meeting the Research Diagnostic Criteria for insomnia. PST was revealed to show some promise as an adjunctive intervention for insomnia, with comparable results to CT on diary and self-report measures of sleep, and on a secondary measure of worry. Dysfunctional beliefs about sleep and problem-solving orientation improved variably over time across treatments, suggesting different mechanisms of action. Implications for the future application of problem-solving interventions in insomnia are discussed.