Long-term effects of chronic khat use: impaired inhibitory control
- 1 Cognitive Psychology Unit, and Leiden Institute for Brain and Cognition, Leiden University, Leiden, Netherlands
- 2 Department of Psychology, Granada University, Granada, Spain
- 3 Amsterdam Center for the Study of Adaptive Control in Brain and Behaviour, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
So far no studies have systematically looked into the cognitive consequences of khat use. This study compared the ability to inhibit and execute behavioral responses in adult khat users and khat-free controls, matched in terms of age, race, gender distribution, level of intelligence, alcohol and cannabis consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non-users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop signals than non-users.
Keywords: khat, SSRT, dopamine, stop-signal task, chronic use, long-term effect
Citation: Colzato LS, Ruiz MJ, van den Wildenberg WPM, Bajo MT and Hommel B (2011) Long-term effects of chronic khat use: impaired inhibitory control. Front. Psychology 1:219. doi: 10.3389/fpsyg.2010.00219
Received: 21 September 2010;
Accepted: 18 November 2010;
Published online: 12 January 2011.
Edited by: Anna M. Borghi
, University of Bologna and Institute of Cognitive Sciences and Technologies, Rome, Italy
Copyright: © 2011 Colzato, Ruiz, van den Wildenberg, Bajo and Hommel. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Lorenza S. Colzato, Institute of Psychology, Department of Psychology, Cognitive Psychology Unit, Leiden University, Postbox 9555, 2300 RB Leiden, Netherlands. e-mail: email@example.com