Chunk #11 — 3. Results — 3.2 Association of Suicide with Current Smoking — 3.2.1. Possible Mechanisms — 3.2.1.2. Smoking as a Psychological or Physical Toxin
could have influenced prolactin levels by nonserotonergic mechanisms (Anthenelli & Maxwell 2000). Unfortunately, except for the postmortem studies, the above studies were performed only in smokers vs nonsmokers with current alcohol dependence. Also, in these studies, it was unclear whether the control groups of “nonsmokers” were composed of never-smokers only or never-smokers + ex-smokers. Making this distinction is important to determine whether smoker/nonsmoker differences are due to the direct effects of smoking vs some pre-existing phenomena (Hughes 1996). One line of evidence against this mechanism is that depression and suicide have not been common adverse events from acute or chronic dosing of nicotine per se in humans; i.e., in studies of nicotine replacement therapy (NRT) (Greenland et al. 1998). Of course, this may be because the level of nicotine and the rapidity of absorption of nicotine in NRT does not adequately mimic that of nicotine via cigarettes.
