| Autor: |
Fitzpatrick RE; School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Clayton, Australia., Robinson AH; School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Clayton, Australia., Rubenis AJ; School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Clayton, Australia.; Turning Point, Eastern Health, Monash University, Fitzroy, Australia., Lubman DI; Turning Point, Eastern Health, Monash University, Fitzroy, Australia.; Eastern Health Clinical School, Monash University, Fitzroy, Australia., Verdejo-Garcia A; School of Psychological Sciences and Turner Institute for Brain and Mental Health, Monash University, Clayton, Australia.; Turning Point, Eastern Health, Monash University, Fitzroy, Australia. |
| Abstrakt: |
Background : Methamphetamine use disorder (MUD) associates with cognitive impulsivity deficits. However, few studies have examined longitudinal changes in cognition, and it remains unclear if deficits resolve during early recovery. Objectives : To compare: (1) cognitive function of individuals with MUD at treatment onset and six-weeks later with controls tested over the same period; (2) cognitive changes in MUD-individuals who remained abstinent versus relapsed. Method : We recruited 108 participants meeting DSM-IV-TR criteria for methamphetamine dependence (81 males) and 50 demographically matched controls (38 males); 77 methamphetamine- dependent participants (59 males) and 48 controls (36 males) were retained at follow-up. We administered response inhibition, delay discounting and uncertainty-based decision-making tests at both endpoints. Relapse was defined as methamphetamine concentrations >0.4 ng/mg at follow-up in hair toxicology. Results : We found a significant time-by-group interaction on uncertainty-based decision-making (effect size: η 2 = .05), although post-hoc tests to disentangle this interaction yielded inconclusive results ( p -range = .14-.40; BF 10 -range = 0.43-1.67). There were no significant time-by-group interactions on response inhibition or delay discounting, with the former likely a null effect ( η 2 -interaction = .003 and .02; BF incl = 0.23 and 0.71). There were no significant differences in cognitive recovery between individuals who maintained abstinence (n = 12) versus relapsed (n = 65) ( η 2 -range = .003-.04), although evidence was inconclusive toward whether findings reflected true null effects ( BF incl -range = 0.33-0.75). Conclusion : We did not find evidence that MUD-related cognitive impulsivity deficits improve beyond practice effects over 6 weeks. Findings do not support previous, albeit conflicting, evidence of early recovery of cognitive deficits in MUD. |
