Daamen, Marcel; Specht, Karsten; Reul, Jürgen; Schuetz, Christian G. Friedrich-Wilhelm-University, Bonn/ University of Bergen, Norway/ KKH Siegen, Germany/ Ruhlmann, Jürgen, Medicine Center Bonn, Bonn, Germany/ Friedrich-Wilhelms-University Bonn, Bonn, Germany
We investigated smoking cue-induced brain activities in recently abstinent smokers recruited from a smoking cessation program. A total of 20 subjects were included in the study. Six subjects had to be excluded due to technical problems or subjects’ violations of the protocol. At the time of testing, subjects were abstinent for ten days on average. Participants were shown pictures with smoking-related, neutral or control stimuli, each for 4 seconds (plus a 10 second resting period). Current level of nicotine craving (scale 0-6) was assessed immediately before and after scanning. During the experiment, a total of 504 gradient echo EPI-volumes (TR=2500 ms, TE=50 ms, flip angle=90, 24 transversal slices parallel to AC-PC-line, FOV=220x220, in-plane resolution=64x64, 5 mm thickness, gap 0.5 mm) were acquired on a 1.5T Siemens MR scanner. Spatial preprocessing and statistical data analyses were conducted using SPM2. Smoke, neutral and control picture onsets were modelled as HRF regressors in an event-related design, including additional regressors for temporal derivatives and realignment parameters. Contrast images for the comparison “smoking minus neutral” were computed on single subject level, and entered into a “random-effects” correlational analysis, with craving level as covariate. Craving levels were positively correlated with higher activation levels (voxelwise p<.001 uncorr., cluster size k>10 voxels) in a large region of the posterior cingulate. Further activations were seen in the dorsal anterior cingulate, anterior insula, and motor-related areas. These data extend previous reports of cue-induced brain activity in smokers, which mostly studied active smokers with abstinence durations <24h. The correlational relationship to experienced craving level emphasizes the role of the affective withdrawal status in cue reactivity.