1. ¹Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
2. ²VA Connecticut Healthcare System, West Haven, CT, USA
3. ³Institute for Neurodegenerative Disorders, New Haven, CT, USA

Correspondence: Dr KP Cosgrove, Department of Psychiatry, Yale University School of Medicine and the VA Connecticut Healthcare System, 116A6, 950 Campbell Avenue, West Haven, CT 06516, USA. Tel: +1 203 932 5711 ext. 3329; Fax: +1 203 937 3897; E-mail: kelly.cosgrove@yale.edu

Received 17 September 2008; Revised 20 March 2009; Accepted 23 March 2009; Published online 13 May 2009.

Abstract

Tobacco smoking is highly comorbid with heavy alcohol drinking, yet the interaction of tobacco smoking and alcohol drinking on brain catecholaminergic synaptic markers is unexplored. Here we evaluate the effects of alcohol drinking alone from comorbid alcohol drinking and tobacco smoking on dopamine (DA) and serotonin (5-HT) transporter availability. A total of 14 heavy alcohol drinking smokers (n=6) and nonsmokers (n=8) and 14 age-matched control smokers (n=6) and nonsmokers (n=8) were imaged with [¹²³]-CIT single photon emission computed tomography. Alcohol drinking smokers and nonsmokers consumed 134.3100.3 and 196.5139.9 drinks, respectively, over the previous month and were imaged during acute withdrawal, eg within 5 days of their last drink. Striatal DA transporter availability was significantly higher (16%, P=0.04) in alcohol drinkers compared to controls. 5-HT transporter availability was also significantly higher in alcohol drinkers vs controls in the brainstem (25%, P=0.001) and the diencephalon (8%, P=0.01). This elevation was restricted to alcohol drinking nonsmokers with higher DA transporter availability in the striatum (26%, P=0.006), and higher 5-HT transporter availability in the diencephalon (26%, P=0.04) and brainstem (42%, P<0.0002). There was a significant positive correlation between days since last drink and 5-HT transporter availability in the diencephalon (r=0.60, P=0.023) and brainstem (r=0.54, P=0.047), in the total group of alcohol drinkers and in the nonsmokers, but not the smokers. During the first week of abstinence, DA and 5-HT transporter availability is higher in alcohol drinking nonsmokers but not in alcohol drinking smokers. Smoking appears to suppress neuroadaptive changes in DA and 5-HT transporters during acute withdrawal from alcohol.