Abstract
Objective: This study aimed to investigate the impact of comorbid obsessive–compulsive symptoms (OCS) on neurocognitive functioning and psychopathology in people with schizophrenia according to stage of illness.
Methods: This study enrolled 163 people with schizophrenia who were receiving risperidone monotherapy. Comorbid OCS were assessed using the Yale–Brown Obsessive Compulsive Scale, and subjects with a score of 10 or higher constituted the OCS group. Neurocognitive functioning, psychopathology, and quality of life were compared according to the presence of OCS in the total population and among populations with <5 and ≥5 years of illness duration.
Results: A total of 30 patients (18.4%) had OCS. In the early-stage group (duration of illness <5 years), the learning index on the verbal learning test was significantly higher in the OCS than in the non-OCS group. In the chronic-stage group (duration of illness ≥5 years), the backward digit span was significantly lower in the OCS than in the non-OCS group. In both stages of illness groups, scores on positive and general psychopathology subscales and total Positive and Negative Syndrome Scale, Calgary Depression Scale for Schizophrenia, and Beck Depression Inventory scores were significantly higher in the OCS than the non-OCS subgroup. Additionally, the Subjective Well-being under Neuroleptic Treatment-Short Form score was significantly lower in the OCS than in the non-OCS group.
Conclusion: The relationship between OCS and neurocognition in patients with schizophrenia is dependent on stage of illness. However, schizophrenia patients with OCS had greater psychotic and depressive symptoms and poorer quality of life regardless of illness stage.