Emotionally valenced stimuli impact response inhibition in those with substance use disorder and co-occurring anxiety and depression symptoms

Background: Substance use disorder (SUD) is associated with impaired response inhibition. Given the deficits in emotion regulation associated with SUD, it is unclear if this impairment is exacerbated by emotionally valenced stimuli. Co-occurring conditions may further exacerbate these impairments as many co-occurring conditions further impact emotion regulation. It was hypothesized that negative stimuli may further impact response inhibition for this population. Methods: The current study used the stop-signal task to examine response inhibition to negative, neutral and positive stimuli in a sample of those with a history of SUD and co-occurring depression and anxiety symptoms. Results: Response inhibition was poorer for negative stimuli relative to neutral stimuli. There was no difference between negative and positive stimuli. Depression severity moderated the difference between response inhibition for negative and neutral stimuli. At elevated depression, response inhibition was worse and there was no difference across emotional stimuli. At low depression, there was a significant difference between negative and neutral stimuli. This effect was not found for anxiety symptoms. Limitations: Study participants presented with polysubstance use of varying duration and amount. It is unclear whether findings are attributed to specific substances, or substance use broadly. Additionally, happy, angry, and calm facial emotions were used to represent positive, negative, and neutral valences respectively. It is unclear whether these findings are generalizable to other emotional expressions. Conclusion: Results suggested that emotionally valenced stimuli affected response inhibition among those with low symptom severity. At elevated symptom severity, response inhibition to all stimuli were impaired.