Objective: To explore the association between eating disorders (EDs) prior to the use of clozapine/olanzapine (pre-clozapine/olanzapine EDs) and after initiation of these antipsychotics (post-clozapine/olanzapine EDs).
Method: Sixty-four consecutively admitted patients receiving clozapine/olanzapine were screened using the M-Composite International Diagnostic Interview (M-CIDI) to identify subjects with pre-clozapine/olanzapine EDs (DSM-IV criteria). We investigated post-clozapine/olanzapine EDs and binge eating behavior using the Questionnaire on Eating and Weight Patterns (QEWP) and used the Naranjo probability scale as objective causality assessment.
Results: Post-clozapine/olanzapine EDs were significantly more frequent in patients with pre-clozapine/olanzapine EDs (5 of 6) when compared to patients without pre-clozapine/olanzapine EDs (4 of 58) [chi(2) = 26.29; df = 1; p < 0.001] [odds ratio (OR) 67.5; 95% CI: 6.3-725.8]. According to the Naranjo probability scale, recurrence or deterioration of EDs in patients with prior EDs was definitely (n = 1) or probably (n = 4) related to the intake of clozapine/olanzapine.
Conclusion: Clozapine/olanzapine may induce recurrence or deterioration of binge eating symptomatology or full-blown EDs in patients with prior EDs.