Marie‐Claude Pélissier

Beyond Reasonable Doubt: Reasoning Processes in Obsessive-Compulsive Disorder and Related Disorders

Traditionally, obsessive-compulsive disorder has been classified as an anxiety disorder, but there is increasing evidence that it has schizotypal features ? in other words it is a belief disorder. Beyond Reasonable Doubt moves comprehensively through theoretical, experimental, clinical and treatment aspects of reasoning research, and contains a detailed treatment manual of great value to practitioners, including assessment and treatment protocols and case studies

Cognitive behaviour therapy and medication in the treatment of obsessive–compulsive disorder

Objective:  To compare cognitive behaviour therapy (CBT) with CBT plus medication; medication alone; and placebo in the treatment of adult obsessive–compulsive disorder (OCD).

Treating Delusional Disorder: A Comparison of Cognitive-Behavioural Therapy and Attention Placebo Control

Objective: Cognitive-behavioural therapy (CBT) has proved effective in treating delusions, both in schizophrenia and delusional disorder (DD). Clinical trials of DD have mostly compared CBT with either treatment as usual, no treatment, or a wait-list control. This current study aimed to assess patients with DD who received CBT, compared with an attention placebo control (APC) group. Method: Twenty-four individuals with DD were randomly allocated into either CBT or APC groups for a 24-week treatment period. Patients were diagnosed on the basis of structured clinical interviews for mental disorders and the Maudsley Assessment of Delusion Schedule (MADS). Results: Completers in both groups (n = 11 for CBT; n = 6 for APC) showed clinical improvement on the MADS dimensions of Strength of Conviction, Insight, Preoccupation, Systematization, Affect Relating to Belief, Belief Maintenance Factors, and Idiosyncrasy of Belief. Conclusion: When compared with APC, CBT produced more impact on the MADS dimensions for Affect Relating to Belief, Strength of Conviction, and Positive Actions on Beliefs.

Inductive reasoning and doubt in obsessive compulsive disorder

BACKGROUND AND OBJECTIVES Previous studies show that individuals with obsessive compulsive disorder (OCD) accord more importance than healthy controls (HC) to alternative conclusions, resulting in increased doubt regarding an initial conclusion. The goal of the present study was to replicate and extend this finding. METHODS Eighteen participants diagnosed with OCD and 16 HC completed the Reasoning with Inductive Arguments Task (RIAT), which operationalizes doubt as change in confidence towards a conclusion after alternative conclusions are presented. To examine conditions that facilitate doubt, the impact of alternative conclusions that both supported and contradicted the initial conclusion was compared, as well as the effect of neutral and OCD-relevant item content. RESULTS Both the OCD and HC groups decreased confidence after contradicting conclusions, but only the HC group increased confidence when presented with supporting conclusions. Furthermore, decrease in confidence in the OCD group correlated with OCD symptom severity. LIMITS The RIAT could be adapted to better take into account of OCD subtypes. CONCLUSION Doubt generation may contribute to obsessional doubting.