Neural reward response to substance-free activity images in opiate use disorder patients with depressive symptoms.

Background: Deficits in the ability to experience reward from natural, substance-free activities and stimuli is a common mechanism contributing to both opiate use disorder and depressive symptoms, and is a target of behavioral-focused treatments for substance use and depression. Although the neural response to monetary, positive affect-eliciting and social images has been investigated, the neural response to images representing substance-free activity engagement remains untested. The current study tested the neural response to anticipation and receipt of substance-free activity engagement images and monetary reward in opiate use disorder patients with elevated depressive symptoms compared to healthy controls.

Methods: Sixteen male opiate use disorder detoxification patients with elevated depressive symptoms (Beck Depression Inventory (BDI-II) ≥ 14) (OUDD M = 32.19 years, SD = 8.17 years) and seventeen male healthy controls (BDI-II < 14) (HC: M = 26.82 years, SD = 5.29 years) completed the Monetary Incentive Delay (MID) and newly developed Activity Incentive Delay (AID) tasks. Within- and between-group whole-brain contrasts tested activation during anticipation ([reward]-[non-reward]) and receipt ([win]-[non-win]) of substance-free activity image, monetary, and substance-free activity relative to monetary (AID-MID), reward.

Results: OUDD demonstrated significantly lower activation in reward regions during anticipation and significantly greater activation during receipt of substance-free activity image reward compared to HC. OUDD demonstrated significantly lower activation during anticipation of substance-free activity reward relative to monetary reward, compared to HC.

Conclusions: The observed reduction in frontostriatal response to reward anticipation of substance-free activity engagement images in OUDD, yet increased neural response to reward receipt, supports theory linking reductions in reward processing with deficits in motivation for substance-free activity engagement.