Efficacy of Low-dose Olanzapine in Combination with Sertraline on Negative Symptoms and Psychosocial Functioning in Schizophrenia: A Randomized Controlled Trial

Background: Evidence for the efficacy of a low dose of olanzapine (OLA) in combination with antidepressants has been limited and without positive trials in first-episode (FE) patients with schizophrenia (SCH). This study aimed to compare the efficacy in treating negative and depressive symptoms between those FE patients with SCH treated with a combination of OLA plus sertraline and those treated with OLA monotherapy. Methods: One hundred and ninety-six first-episode and drug naïve patients with SCH were randomized to receive low-dose OLA (7.5-10 mg/day) combined with sertraline (50-100 mg/day) (OS group) or normal-dose OLA monotherapy (12.5-20 mg/day) (NO group). Clinical symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS), and the depressive symptoms were evaluated by the Hamilton Depression Scale (HAMD). Psychosocial functioning was assessed by the Personal and Social Performance Scale (PSP). Results: In the intent-to-treat efficacy analysis, the OS group had greater decreases in negative and depressive symptoms (pall < 0.01) and a greater increase in PSP total score compared with the NO group (p < 0.01). Moreover, reductions in HAMD total score and PANSS negative subscore and sex were associated with the improvements in psychosocial functioning from baseline to week 24, after controlling for baseline psychosocial function, age, and onset age. Conclusion: This study demonstrates that low-dose OLA in combination with sertraline had clinically meaningful improvements not only in the negative and depressive symptoms but also in psychosocial functioning in patients with FE-SCH, while not affecting positive symptoms.