The above section dealt only with the association of suicide and current smoking. Whether longer term cessation would be expected to be associated with increased suicide differs across the three explanations in Table 1. The “marker” explanation would predict any association would remain but would still be due to confounds. The psychological/physical toxin theory would predict that since cessation would stop the toxic effects of smoking, there should be no association of suicide with former smoking. The exception would be if one hypotheses that some of the toxic effects of smoking are irreversible; e.g., if smoking caused a painful and debilitating disease that continues after smoking cessation. Finally, the self-medication theory would predict that suicide behavior should increase with abstinence as smoking is no longer present to abate suicidal ideation.
