Heavy smoking linked to increased risk for suicide in schizophrenia
MedWire News: Patients with schizophrenia who smoke heavily have a higher risk for suicide than those who do not smoke, suggest study findings.
"Heavy smoking may serve as an important clinical marker of suicide risk in individuals with schizophrenia, especially among females," say Yu-Chen Kao (Songshan Armed Forces General Hospital, Taipei, Taiwan) and co-authors.
The findings are of importance, as the prevalence of cigarette smoking is significantly higher among individuals with schizophrenia compared with the general population.
Over a 1-year period, 95 outpatients with a DSM-IV diagnosis of schizophrenia were interviewed about their past and current cigarette smoking. In addition, patients were evaluated for clinical course, social functioning, suicide risk, psychopathology, antipsychotic-induced side effects, impulsivity, depression, anxiety, and pessimism.
The researchers found that 65% of patients classified as smokers smoked more than 20 cigarettes per day, and met DSM-IV criteria for nicotine dependence.
Smoking initiation and illness onset occurred earlier among males than females, at 17.6 versus 20.7 years, and 23.9 versus 25.9 years, respectively.
Compared with nonsmokers, patients who smoked had a significantly higher rate of lifetime suicide attempts, 65% versus 39%. They also had higher hospitalization rates, antipsychotic treatment side effects, psychopathology, impulsivity, depression, anxiety, and suicidal risk.
Multivariate regression analysis showed that tobacco use, depressive symptoms, anxiety symptoms, and the attentional component of impulsivity were significantly related to suicidality.
When the team analyzed these findings according to gender, they found that depressive symptoms were significant predictors for suicidality among males, while heavy smoking, anxiety symptoms, and hopelessness were significant predictors among females.
"Our findings suggest that additional research focusing on these demographic and clinical factors would increase our understanding of the effect of smoking on overall suicidality in individuals with schizophrenia," conclude the study authors in the journal Psychiatry Research.
By Ingrid Grasmo