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Aims: This study aimed to test whether there are sex differences in the relationship between impulsivity and amphetamine use disorder (AMP). Design: A naturalistic cross‐sectional design was used. Setting: The Tulsa 1000 study was held in Tulsa, OK, USA. Participants: There were two groups in this study: AMP+ (29F, 20M) and AMP– (57F, 33M). Measurements This project focuses on data related to impulsivity: UPPS‐P impulsive behavior scale and a stop signal task (SST) during functional magnetic resonance imaging (fMRI) recording. Group, sex and their interaction were compared for UPPS‐P ratings and SST fMRI and behavioral responses. Findings AMP+ reported higher UPPS‐P positive and negative urgency scores (Ps < 0.001; r = 0.56 and 0.51) and displayed greater bilateral insula and amygdala responses across correct SST trials (Ps < 0.001, g range = 0.57–0.81) than AMP–. fMRI results indicated that AMP+ exhibited larger right anterior/middle insula, amygdala and nucleus accumbens signals during successful difficult stop trials than AMP– (Ps < 0.01; g = 0.63, 0.54 and 0.44, respectively). Crucially, two group × sex effects emerged: (a) within females, AMP+ reported larger UPPS‐P lack of premeditation scores than AMP– (P < 0.001, r = 0.51), and (b) within males, AMP+ showed greater left middle insula signals than AMP– across correct SST trials (P = 0.01, g = 0.78). Conclusions: Both female and male amphetamine users appear to be characterized by rash action in the presence of positive and negative mood states as well as heightened recruitment of right hemisphere regions during behavioral inhibition. In contrast, planning ahead may be particularly difficult for female amphetamine users, whereas male amphetamine users may need to recruit additional left hemisphere resources during inhibitory processing. [ABSTRACT FROM AUTHOR]

Background: Repetitive negative thinking (RNT), particularly its brooding aspect, is a prominent feature in Major Depressive Disorder (MDD) with and without comorbid anxiety. Error processing, an adaptive cognitive operation, seems to be impaired in individuals with exaggerated RNT. This study measured a post-error neural response, error-related negativity (ERN), during an inhibitory task to examine the mechanism underlying the relationship between RNT and faulty error processing., Methods: We examined current MDD patients with (n = 61) and without comorbid anxiety disorders (COM; n = 38), propensity-matched into High- or Low-RNT groups according to Ruminative Response Scale Brooding subscale scores. Using 32-channel electroencephalography (EEG) during a stop-signal task, we measured baseline-corrected ERN amplitude at FCz 0-100 ms after an incorrect response. A between-subjects ANOVA was conducted with group (High RNT, Low RNT) and comorbidity (MDD, COM) as factors., Results: A significant group-by-comorbidity interaction (η 2  = 0.07) was found, with MDD participants exhibiting high RNT revealing smaller (more positive) ERN amplitudes compared to their COM counterparts with high RNT (d = 0.77) and MDD participants with low RNT (d = 0.92)., Conclusions: Non-anxious individuals with MDD and high RNT showed blunted post-error neural responses, potentially indicating a diminished adaptive neural mechanism for recognizing and correcting errors. However, the presence of comorbid anxiety disorders in individuals with high RNT appears to counteract this reduction, potentially through an enhanced neural response to errors, thereby maintaining a higher level of error-processing activity. Further understanding of these relationships is essential for developing targeted interventions for MDD, with particular focus on the detrimental impact of brooding RNT., Competing Interests: Declaration of competing interest Martin P. Paulus, M.D. is an advisor to Spring Care, Inc., a behavioral health startup, and has received royalties for an article about methamphetamine in UpToDate. Martin P. Paulus, M.D. has a consulting agreement with and receives compensation from F. Hoffmann-La Roche Ltd. The other authors report no financial relationships with commercial interests related to the present study., (Copyright © 2024. Published by Elsevier B.V.)