Longitudinal study of insomnia, suicidal ideation, and psychopathology in schizophrenia

Objective: Insomnia is a common comorbidity in schizophrenia. Increasing cross-sectional evidence suggests an association between insomnia and suicidal ideation (SI) and symptom severity in schizophrenia. We investigated longitudinal associations over 3 months between insomnia, suicidal ideation, and symptom severity in a group of patients with chronic schizophrenia. Method: We performed a secondary analysis of data from n = 305 participants from the Preventing Relapse Oral Antipsychotics Compared to Injectables Evaluating Efficacy (PROACTIVE) schizophrenia trial using regression models. Results: The prevalence of moderate-to-severe insomnia was 17.7 % at baseline and 13.6 % at 3 months, respectively. The prevalence of SI was 22 % at baseline and 22.5 % at 3 months. After controlling for potential confounders, improved SI from baseline to 3 months was associated with both baseline moderate-to-severe insomnia (OR = 3.81, 95 % CI 1.11–13.12, p = 0.034) and improvement in insomnia (OR = 3.50, 95 % CI 1.23–9.92, p = 0.013). Worsening SI from baseline to 3 months was associated with worsening insomnia (OR = 3.50, 95 % CI 1.23–9.92, p = 0.013), but not baseline insomnia. Improvement in BPRS total score from baseline to 3 months was associated with improvement in insomnia (β = 0.17, p = 0.029), but not baseline insomnia. Conclusion: Insomnia is common in patients with chronic schizophrenia and insomnia showed significant associations with SI and psychopathology. Clinicians should consider insomnia when assessing suicide risk in patients with schizophrenia.