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.