The following is a summary of “Role of psychosis and clozapine load in excessive checking in treatment-resistant schizophrenia: longitudinal observational study,” published in the April 2024 issue of Psychiatry by Fernandez-Egea et al.
Many individuals with schizophrenia who undergo clozapine treatment develop ‘checking’ compulsions, but the reason behind this is yet to be known.
Researchers conducted a retrospective study investigating how psychosis, clozapine dose, and obsessive-compulsive symptoms (OCS) interact using habit formation models developed in cognitive neuroscience.
They analyzed anonymized electronic records of patients treated with clozapine, examining longitudinal data on OCS and psychosis. Using multi-level mediation and moderation analyses, the correlation between psychosis and obsessiveness and checking behaviors was analyzed. Clozapine dose and checking compulsions were assessed via bivariate correlation tests, and the influence of genetic variants was examined in a subsample.
The results showed that 196 clozapine-treated individuals and 459 face-to-face assessments were included. Significant obsessive-compulsive symptoms were found in 37.9% of cases, with checking being the most common symptom. Psychosis severity indirectly influenced checking behavior through obsessions (r=0.07, 95% CI 0.04-0.09; P<0.001). However, no direct correlation between psychosis and checking was identified (r= -0.28, 95% CI -0.09 to 0.03; P=0.340). After psychosis remission (n=65), checking compulsions correlated with clozapine plasma levels (r=0.35, P=0.004) and dose (r=0.38, P=0.002). Glutamatergic and serotonergic genetic variants did not moderate this effect.
Investigators concluded that by understanding how psychosis and compulsions interact, clinicians can make better treatment choices.