Sex Differences in the Prevalence and Clinical Features of Comorbid Depressive Symptoms in Never-Treated Chinese Patients With First-Episode Schizophrenia

Background: Many studies have indicated a sex-specific effect in many aspects of schizophrenia. The presence of depressive symptomatology exists in all phases of schizophrenia. The aim of this study is to investigate the sex differences in the proportion of comorbid depressive symptoms and sex-specific relationships between depressive symptoms and clinical correlates in never-treated Chinese patients with first-episode schizophrenia (NTFE patients), which have not been reported yet.

Methods: Via a cross-sectional design, 240 NTFE inpatients (male/female = 111/129) between ages 16 and 45 years and meeting DSM-IV-TR criteria of schizophrenia were recruited. The Positive and Negative Syndrome Scale (PANSS) was used for the psychopathology, and the 17-item Hamilton Depression Rating Scale (HDRS-17) for the comorbid depressive symptoms. This study was conducted from June 2013 to December 2015.

Results: The proportion of patients with depressive symptoms (total score on HDRS-17 ≥ 8) in men was significantly higher than in women (male: 62.2%, female: 48.1%; χ21 = 4.28, P = .039). Male patients had significantly greater depressive symptoms as shown on the HDRS-17 than female patients (t1, 238 = 2.75, P = .006). Further, we found that age, the age at onset, smoking rate, and PANSS total and general psychopathology, negative symptoms, and cognitive factor subscores favored significant sex differences in female patients (all P < .05). Interestingly, we found sex differences in the correlation between the HDRS-17 score and clinical phenotype, showing that in male patients, the PANSS general psychopathology subscore (β = 0.75, t = 7.72, P < .001) and total score (β = 0.44, t = 4.81, P < .001) significantly predicted the HDRS-17 total score, while in female patients, the PANSS general psychopathology subscore (β = 0.74, t = 8.45, P < .001), total score (β = 0.47, t = 5.71, P < .001), and cognitive factor subscore (β = 0.24, t = 2.60, P < .001) significantly predicted the HDRS-17 total score.

Conclusions: Our results indicate sex differences in the frequency and severity of comorbid depressive symptoms and in associations between depressive symptoms and clinical correlates in NTFE patients.