Substance use disorders and the orbitofrontal cortex: systematic review of behavioural decision-making and neuroimaging studies.

BACKGROUND Orbitofrontal cortex dysfunctions have been frequently documented in people with substance use disorders. The exact role of this cortical region, however, remains unspecified. AIMS To assess the functionality of the orbitofrontal cortex in people with substance use disorders. METHOD Reports of studies using behavioural decision-making tasks and/or neuroimaging techniques to investigate orbitofrontal cortex functioning in cases of substance misuse were reviewed. Studies focusing exclusively on tobacco-smoking and gambling were excluded. RESULTS Fifty-two research articles were evaluated. Most studies showed significant deficits in decision-making in people with substance use disorders. A consistent finding in the neuroimaging studies was hypoactivity of the orbitofrontal cortex after detoxification. The association between hyperactivity of this region and craving or cue reactivity was not consistent across studies. CONCLUSIONS The orbitofrontal cortex has an important role in addictive behaviours. Further studies are needed to elucidate the underlying neuronal substrates of cue reactivity, craving and decision-making, and the implications for treatment and relapse prevention.