BJ Miller, CB Parker, MH Rapaport, PF Buckley and WV McCall,
Sleep, Nov 2018 08
Insomnia is a common symptom in the clinical course of schizophrenia. There is a robust association between insomnia and suicidality in other psychiatric disorders. Two previous studies found associations between insomnia and suicide attempt or completed suicide in patients with schizophrenia. We hypothesized that greater insomnia would be associated with greater levels of suicidal ideation in patients with schizophrenia and other non-affective psychoses.We recruited 108 inpatients and outpatients age 18-65 between July 2010 and July 2016 with DSM-IV non-affective psychosis (schizophrenia, schizoaffective disorder, or schizophreniform disorder). We investigated relationships between current insomnia (Insomnia Severity Index [ISI]), suicidal ideation over the past week and lifetime history of suicide attempt (Beck Scale for Suicide Ideation [BSS]) in regression analyses.After controlling for potential confounders, insomnia was a significant indicator of suicidal ideation (β=0.27, p=0.032). Insomnia was also a significant indicator of a high BSS score (≥16), (OR=1.14, 95% CI 1.01-1.28, p=0.029). Furthermore, subjects with severe insomnia were almost 15 times more likely to have a lifetime history suicide attempt than subjects without current insomnia (OR=14.8, 95% CI 1.4-157, p=0.025). Insomnia was also an indicator of greater PANSS total (β=0.33, p=0.001), positive subscale (β=0.32, p=0.002), and general subscale (β=0.40, p<0.001) scores.Insomnia is associated with suicidal ideation, lifetime suicide attempt, and greater psychopathology in patients with schizophrenia. Our findings suggest that formal assessment of insomnia may be germane to the clinical care of patients with schizophrenia as a marker of suicide risk and symptom severity.