Baseline and post-amphetamine dlPFC D2R availability for all subgroups. Female smokers (black circles) showed significantly less amphetamine-induced DA release in the dlPFC than both male smokers (black squares) and female nonsmokers (gray circles). Male nonsmokers are shown in gray squares. Open shapes represent pre-amphetamine data and closed shapes represent post-amphetamine data. Group mean %ΔBPND is shown above data points. BPND = binding potential, FNS = female nonsmokers, FS = female smokers, MNS = male nonsmoker, MS = male smoker, Pre = pre-amphetamine, Post = post-amphetamine