Smoking predicts suicidality: findings from a prospective community study.

Background: The temporal relationship between smoking and suicidality is not yet clear. This article examines associations between smoking and suicidality and their temporal ordering of onset.
Methods: Baseline and four-year follow-up data were used from the Early Developmental Stages of Psychopathology (EDSP) study, a prospective longitudinal study of adolescents and young adults in Munich, Germany. We assessed smoking (occasional and regular), nicotine dependence, suicidal ideation and suicide attempts using the standardized Munich-Composite International Diagnostic Interview (M-CIDI).
Results: Suicide ideation and suicide attempts were strongly associated with occasional and regular smoking and nicotine dependence at baseline (Odds ratios [OR] range from 1.4 to 16.4). In the prospective analyses, prior occasional, regular smoking and nicotine dependence increased the risk for new onset of suicide ideation (OR range from 1.5 to 2.7) and prior regular smoking and nicotine dependence increased also the risk for onset of suicide attempt(s) (OR range between 3.1 and 4.5). Pre-existing suicidality could not be shown to be associated with subsequent smoking or nicotine dependence. Associations remained stable when participants who fulfilled DSM-IV-criteria for major depression were excluded.
Limitations: The sample is confined to an age cohort of 14 to 24 years. No completed suicides could be observed.
Conclusions: The presence of associations between prior smoking and subsequent suicidality, in concert with the lack of associations between prior suicidality and subsequent smoking suggests the existence of an independent pathway from smoking to suicidality.