Associations between processing of affective and drug-related stimuli and illicit opioid use in people prescribed opioid substitution therapy

Introduction and Aims: Blunted responses to pleasant stimuli and exaggerated responses to drug‐related stimuli have been observed in substance use disorders. Recent research suggests these alterations may prospectively predict substance use. However, few of these studies have examined people with opioid use disorder, and they have typically examined categorical substance use outcomes, rather than continuous outcomes. We examined cross‐sectional and predictive relationships between altered response to drug‐related, pleasant and unpleasant images and frequency of illicit opioid use in people prescribed opioid substitution therapy for opioid use disorder.

Design and Methods: The startle‐elicited event‐related electroencephalograph potential P300 component (which indexes attention allocation) was measured in 82 participants prescribed opioid substitution therapy while they viewed pleasant, unpleasant, drug‐related and neutral pictures. Participants also provided ratings of how pleasant and arousing they found these pictures. Frequency of past‐month illicit opioid use was measured at baseline, and monthly for the following six months. Relationships between picture responses and illicit opioid use were analysed using mixed effects regression modelling.

Results: Increased frequency of illicit opioid use at baseline was associated with less attenuation of startle‐elicited P300 amplitude during pleasant pictures, and with higher arousal ratings of drug pictures. However, image response measures did not predict future opioid use.

Discussions and Conclusions: Illicit opioid use was associated with both reduced attention to pleasant stimuli and increased arousal to drug‐related stimuli, but these changes did not predict later opioid use. This is consistent with these changes in stimulus processing being a consequence, but not a cause, of drug use.