Comparison of cognitive functions and other clinical correlates in patients with schizophrenia with and without comorbid obsessive-compulsive disorder

Context
Schizophrenia is a serious and chronic mental disorder that includes a variety of cognitive, behavioral, and emotional symptoms, and it can be difficult to diagnose.
Aims
To compare cognitive functions and psychotic parameters, the association of depressive symptoms, and the overall level of performance among individuals with schizophrenia only and individuals who had schizophrenia with comorbid obsessive-compulsive disorder (OCD).
Settings and design
The study was conducted at the Neuropsychiatry Department and the Center of Psychiatry, Neurology, and Neurosurgery of Tanta University.
Patients and methods
This study was carried out on 60 patients aged from 18 to 40 years who were able to read and write. Patients were subdivided into two equal groups: group 1 met the diagnosis of schizophrenia with OCD according to Diagnostic and Statistical Manual of Mental Disorders-IV criteria and group 2 fulfilled the diagnosis of schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders-IV criteria. All cases were subjected to psychiatric interview, psychiatric symptom rating, neuropsychological assessment, and global assessment of functioning.
Statistical analysis
SPSS v25 was used to perform the statistical analysis.
Results
Patients who had schizophrenia with OCD showed a considerably greater score on Hamilton depression rating scale than patients with schizophrenia only (=0.002). Patients with schizophrenia only showed more negative symptoms than those who had schizophrenia with OCD (=0.001).
Conclusions
Schizo-obsessive patients have better performance in all cognitive tests, showing higher levels of concentration and visuospatial functioning and better visual search speed, scanning, speed of processing, and abstract thinking. Moreover, they had higher levels of overall social and occupational functioning. Important clinical consequence of our work is that schizo-obsessive cases do not inevitably have a more severe disease with a potentially worse prognosis.