Original Research ARTICLE
Methamphetamine users show no behavioral deficits in response selection after protracted abstinence
- 1Universitätsklinikum Carl Gustav Carus, Germany
Chronic recreational methamphetamine use causes dopaminergic neurotoxicity, which has been linked to impairments in executive functioning. Within this functional domain, response selection and the resolution of associated conflicts have repeatedly been demonstrated to be strongly modulated by dopamine. Yet, it has never been investigated whether chronic methamphetamine use leads to general impairments in response selection (i.e., irrespective of consumption-associated behavior) after substance use is discontinued.
We tested n=24 abstinent methamphetamine users (on average 2.7 years of abstinence) and n=24 individually matched controls in a cross-sectional design with a flanker task.
Compared to healthy controls, former methamphetamine consumers had significantly slower reaction times, but did not show differences in the size of the flanker or Gratton effect, or post-error slowing. Complementary Bayesian analyses further substantiated this lack of effects despite prior consumption for an average of 7.2 years.
The ability to select a correct response from a subset of conflicting alternatives, as well as the selective attention required for this seem to be largely preserved in case of prolonged abstinence. Likewise, the ability to take previous contextual information into account during response selection and to process errors seem to be largely preserved as well. Complementing previously published finding of worse inhibition/interference control in abstinent consumers, our results suggest that not all executive domains are (equally) impaired by methamphetamine, possibly because different cognitive processes require different levels of dopamine activity.
Keywords: Methamphetamine abstinence, response selection, flanker effect, Gratton effect, error processing, Dopamine
Received: 03 Jul 2019;
Accepted: 17 Oct 2019.
Copyright: © 2019 Bensmann, Ernst, Rädle, Opitz, Beste and Stock. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Ann-Kathrin Stock, Universitätsklinikum Carl Gustav Carus, Dresden, 01307, Lower Saxony, Germany, Ann-Kathrin.Stock@uniklinikum-dresden.de