Probing the Serotonin Transporter Availability among Male Cigarette Smokers: A SPECT Study with [ ¹²³I] ADAM

Objective: Genetic studies have suggested that the serotonin transporter (SERT) could be associated with cigarette smoking. However, evidence from neuroimaging is scarce. The aim of the present study was to examine the SERT availability among cigarette smokers by using single-photon emission computed tomography (SPECT). Methods: Sixteen male smokers and 32 controls were enrolled. The SERT availability was measured by SPECT with a radiotracer, [¹²³I] ADAM, which is highly sensitive and specific to SERT. Results: No significant difference in SERT availability was found between 2 groups in the midbrain (smokers: 2.12 ± 0.70, nonsmokers: 2.13 ± 0.63; P=0.86), basal ganglia (smokers: 0.8 ± 0.30, nonsmokers:0.90 ± 0.39; P=0.95), or thalamus (smokers: 1.14 ± 0.41, nonsmokers: 1.20 ± 0.38; P=0.88). No significant association was found between the SERT availability, and either the breath carbon monoxide level or the score of the Fagerström Test for Nicotine Dependence. Conclusions: Whether the SERT availability in the brain is altered in smokers remains unclear.