Alterations in the processing of non-drug-related affective stimuli in abstinent heroin addicts.
Long-term exposure to drug may alter the neural system associated with affective processing, as evidenced by both clinical observations and behavioral data documenting dysfunctions in emotional experiences and processing in drug addicts. Although many imaging studies examined neural responses to drug or drug-related cues in addicts, there have been few studies explicitly designed to reveal their neural abnormalities in processing non-drug-related natural affective materials. The present study asked abstinent heroin addicts and normal controls to passively view standardized affective pictures of positive, negative, or neutral valence and compared their brain activities with functional MRI. Compared to normal controls, addicts showed reduced activation in right amygdala in response to the affective pictures, consistent with previous reports of blunted subjective experience for affective stimuli in addicts. Furthermore, in two visual cortical areas BA 19 and 37, while the controls showed greater responses to positive pictures than to negative ones replicating literature findings, the addicts showed the opposite pattern. The results reveal a complex pattern of altered processing of non-drug-related affective materials in addicts showing both heightened and blunted neural responses in different brain regions and for different stimulus valence. The present study highlights the importance of brain imaging research on drug addicts' processing of affective stimuli in understanding disruptions in their emotion circuitry.
Wang
Zhao-Xin
ZX
Guangdong Key Lab of Medical Molecular Imaging, the First Affiliated Hospital, Shantou University Medical College, Shantou, China.
Zhang
John X
JX
Wu
Qiu-Lin
QL
Liu
Ning
N
Hu
Xiao-Ping
XP
Chan
Raymond C K
RC
Xiao
Zhuang-Wei
ZW
D000328:Adult; D000339:Affect / Q000502:physiology*; D000679:Amygdala / Q000502:physiology; D001921:Brain / Q000503:physiopathology; D006556:Heroin Dependence / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010775:Photic Stimulation; D017397:Prefrontal Cortex / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D014793:Visual Cortex / Q000502:physiology; D055815:Young Adult