Tobacco Smoking and Medical Co-morbidities among Patients with Bipolar Disorder in a Nigerian Clinical Setting: A Case Control Study

Introduction: Smoking is highly prevalent in patients with bipolar disorder and is associated with medical and psychiatric comorbidities. The main aims of this study were to determine the prevalence and correlates of smoking and the predictors of persistent smoking in patients with bipolar disorder in comparison to a non-psychiatric population, findings of which may be useful in planning a smoking cessation program for the concerned group.

Methods: In this case control study, consecutive patients with bipolar I disorder (BD), (251) were matched by age and gender with the controls who were recruited from the General Outpatients Department (GOPD) of the State Hospital Ibadan, Nigeria between January 2008 and June 2009. Information on demography and tobacco smoking, presence of psychotic symptoms, remission state and self-reports of common health conditions in the past year were obtained. Bivariate associations were determined using Chi square statistics and multivariate analysis was used for further exploration of variables that were significant during bivariate analysis.

Results: Persistent smoking was higher in those with psychotic symptoms, P < .001, those not in remission, P = .01. Persistent smoking was also significantly associated with malignancies, P = .02, cardiovascular diseases, P = .02, respiratory diseases, P = .02, high BMI, P = .02 and chronic pain, P = .001. After adjusting for age and gender, presence of psychotic symptoms OR = 2.89, 95% CI (1.42-5.56), being in remission, OR = 0.49, 95% CI (0.009-0.76), high YMRS scores, OR = 2.63, 95% CI (1.42-5.20), high total PANSS scores OR = 3.23, 95% CI (1.79-6.28) and 3 or more episodes in the past year, OR = 1.89, 95% CI (1.12-4.08) remained associated with persistent smoking.

Conclusion: The present study demonstrates higher rates of lifetime and current smoking among individuals with BD and the association with socio-demographic and clinical factors and highlights the significance of these risk factors in effective tobacco prevention and cessation programs for patients with bipolar disorders.