Investigating the Relationship between Flexibility in Thinking and Treatment Adherence for Individuals with Obsessive Compulsive or Related Disorders and Eating Disorders

Introduction: People with mental disorders characterised by obsessive and compulsive symptoms, such as obsessive-compulsive or related disorders and eating disorders, show poor adherence to mental health treatments, which represents a major clinical challenge. These disorders share a pattern of inflexible thinking, which is thought to influence treatment outcomes. However, there is sparse research exploring the link between cognitive inflexibility and treatment adherence in mental disorders. A Systematic Literature Review investigated the possible link between inflexible thinking and treatment adherence among all forms of mental health disorder. It found evidence that inflexibility in thinking influences treatment adherence among a broad grouping of disorders characterised by poor impulse control and compulsivity. However, no studies were found that explored the link between cognitive inflexibility and treatment adherence among obsessive-compulsive or related disorders and eating disorders. Aim: A cross-sectional study explored the link between cognitive inflexibility and treatment adherence among participants who self-reported having obsessive-compulsive & related disorders and/or an eating disorder and had received some form of mental health treatment. Method: Participants completed an online survey consisting of a Personal Circumstances Questionnaire, Treatment Adherence Rating Scale-Revised, Medication Adherence Rating Scale, WHO-5 Wellbeing Index Scale, Compulsive Personality Assessment Scale and Wisconsin Sorting Card Test-64 card version. Logistic regressions were run, which explored the possible link between cognitive flexibility and treatment adherence. Results: 201 participants (average age 33.77 years, and 168 females) reported a history of obsessive-compulsive & related disorder (n= 169) and/or an eating disorder (n= 92). Logistics regressions found that cognitive inflexibility was associated with therapy adherence (β = -0.11, p ≤ 0.003, OR = 0.89, 95% CI. 0.83 - 0.96). Also, good psychological wellbeing (β = 0.03, p ≤0.008, OR = 1.03, 95% CI. 1.01 – 1.05), as well as male sex at birth (β = 1.68, p ≤ 0.018, OR = 5.36, 95% CI. 1.34 – 21.40), was associated with therapy adherence. No factors were found to linked to medication adherence. Conclusions: Cognitive inflexibility represents a risk factor for poor psychological therapy adherence and could represent a novel biomarker for personalising care for those affected by disorders characterised by obsessive and compulsive symptoms. Clinicians should look for signs of cognitive inflexibility in their patients to aid clinical decision-making.