Smoking worsens outcomes for bipolar patients

by Michael Woodhead

Patients with bipolar disorder or schizoaffective disorder have a poorer prognosis if they are smokers, a prospective two year Melbourne study has shown.

Regular smokers had significantly worse outcomes in terms of bipolar and depression scores compared to non smokers and were also more likely to have longer hospital stays, the study of 240 patients from the Alfred Psychiatry Research Centre found.

The results, published in the journal Comprehensive Psychiatry (online 19 Feb) are yet more reason to encourage smoking cessation in people with mental illness, say the study authors.

As expected, the patients with bipolar disorder had much higher rates of smoking than the general population (51% vs 23%), and smoking was also associated with poorer quality of life overall.

The study authors say there are many possible mechanisms by which smoking could have adverse effect on outcomes form bipolar disorder. Through actions on nicotinic receptors, smoking could aggravate the bipolar cycle, causing more episodic symptoms, increasing the frequency of both affective poles and rapid cycling, they say. Smoking may also interfere with the efficacy and metabolism of psychotropic medications, they say.

However, there is likely to be a two-way interaction between bipolar disorder and smoking, with patients smoking to compensate for some of the effects of the disease, they note.

"There is sufficient evidence to suggest that tobacco smoking should be of concern to clinicians treating patients with bipolar disorder," they conclude.

Patients may be more motivated to quit if they are informed about the additional risks in bipolar outcomes, they suggest.