An explanation for the greater effect of smoking over the posterior versus anterior scalp may be found in the results of radioligand studies (52) wherein nicotine-binding has been shown to be greater in the thalamus and brainstem than in frontal structures and may, over time, be detrimental to their function. Admittedly, though, the literature is not consistent in demonstrating that posterior brain regions are the primary locus (3, 19, 53). The degree to which anterior brain regions are affected in smokers may be related to the chronicity and severity of the habit, as well as its overlap with other disorders, including depression (54) and personality disorder (55).
