The pharmaceutical company Pfizer and the Food and Drug Administration have been arguing back and forth about whether the anti-smoking medication Chantix deserves a black box warning because of patient reports of depression, suicidal impulses, agitation and other psychiatric symptoms. Perhaps these are side effects of Pfizer’s drug, but they might reflect the smoking population including an unusually high proportion of people with pre-existent psychiatric problems.

The smoking population has evolved from what it was before anyone knew smoking was unhealthy. After over a half century of most smokers trying to quit, those still left smoking have become economically poorer and also more psychologically troubled due to adverse selection.

Quitting smoking is easier if you have psychological resources to nurture your motivation, develop a quit plan, tolerate the agitation and bad moods that can come with withdrawal, and cope with urges to relapse. If your emotional resources are already under strain from another problem, such as schizophrenia or depression, you are therefore less likely to succeed at quitting. That’s why smoking and depression were unrelated in 1952, but 40 years after smokers started trying to quit en masse, the prevalence of depression was three times higher among smokers than non-smokers.

Problem drinkers face the same psychological disadvantages as people with mental illnesses, and may also be more prone to relapse because alcohol consumption can neurologically trigger cravings for cigarettes. Remarkably, 53.1% of heavy drinkers smoke, more than triple the rate among non-drinkers.

In this new world of cigarette smoking, reports of psychiatric symptoms among people on smoking cessation pharmacotherapy are going to be common whether the medication in question causes them or not. FDA Regulators must be careful not to overreact when deciding whether to put black box warnings on smoking cessation medications, which scare many people off from taking them.

To go one step further, even when a symptom report truly represents an anti-smoking medication side-effect, smokers, doctors and regulators shouldn’t necessarily rule out the medication as an option. Smoking remains the leading cause of premature death in the United States and taking some calculated risks to continue snuffing it out could be medically and ethically justifiable.

Author’s note: I have no financial relationship with Pfizer and have never accepted so much as a squeezy ball from them during my career.