Catherine Fassbender1, Tyler A Lesh1, Stefan Ursu1, Ruth Salo2. 1. Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, Davis, California. 2. Department of Psychiatry and Behavioral Sciences, University of California Davis Medical Center, Davis, California. Electronic address: resalo@ucdavis.edu.
Abstract
BACKGROUND: This study investigated the dynamics of cognitive control instability in methamphetamine (MA) abuse, as well its relationship to substance-induced psychiatric symptoms and drug use patterns. METHODS: We used an ex-Gaussian reaction time (RT) distribution to examine intraindividual variability (IIV) and excessively long RTs (tau) in an individual's RT on a Stroop task in 30 currently drug-abstinent (3 months to 2 years) MA abusers compared with 27 nonsubstance-abusing control subjects. All subjects underwent functional magnetic resonance imaging while performing the Stroop task, which allowed us to measure the relationship between IIV and tau to functional brain activity. RESULTS: Elevated IIV in the MA compared with the control group did not reach significance; however, when the MA group was divided into those subjects who had experienced MA-induced psychosis (MAP+) (n = 19) and those who had not (n = 11), the MAP+ group had higher average IIV compared with the other groups (p < .03). In addition, although control subjects displayed a relationship between IIV and conflict-related brain activity in bilateral prefrontal cortex such that increased IIV was associated with increased activity, the MAP+ group displayed this relationship in right prefrontal cortex only, perhaps reflecting elevated vigilance in the MAP+ group. Greater IIV did not correlate with severity of use or months MA abstinent. No group differences emerged in tau values. CONCLUSIONS: These results suggest increased cognitive instability in those MA-dependent subjects who had experienced MA-induced psychosis.
BACKGROUND: This study investigated the dynamics of cognitive control instability in methamphetamine (MA) abuse, as well its relationship to substance-induced psychiatric symptoms and drug use patterns. METHODS: We used an ex-Gaussian reaction time (RT) distribution to examine intraindividual variability (IIV) and excessively long RTs (tau) in an individual's RT on a Stroop task in 30 currently drug-abstinent (3 months to 2 years) MA abusers compared with 27 nonsubstance-abusing control subjects. All subjects underwent functional magnetic resonance imaging while performing the Stroop task, which allowed us to measure the relationship between IIV and tau to functional brain activity. RESULTS: Elevated IIV in the MA compared with the control group did not reach significance; however, when the MA group was divided into those subjects who had experienced MA-induced psychosis (MAP+) (n = 19) and those who had not (n = 11), the MAP+ group had higher average IIV compared with the other groups (p < .03). In addition, although control subjects displayed a relationship between IIV and conflict-related brain activity in bilateral prefrontal cortex such that increased IIV was associated with increased activity, the MAP+ group displayed this relationship in right prefrontal cortex only, perhaps reflecting elevated vigilance in the MAP+ group. Greater IIV did not correlate with severity of use or months MA abstinent. No group differences emerged in tau values. CONCLUSIONS: These results suggest increased cognitive instability in those MA-dependent subjects who had experienced MA-induced psychosis.
Authors: W Sturm; A de Simone; B J Krause; K Specht; V Hesselmann; I Radermacher; H Herzog; L Tellmann; H W Müller-Gärtner; K Willmes Journal: Neuropsychologia Date: 1999-06 Impact factor: 3.139
Authors: Penny Andreou; Ben M Neale; Wai Chen; Hanna Christiansen; Isabel Gabriels; Alexander Heise; Sheera Meidad; Ueli C Muller; Henrik Uebel; Tobias Banaschewski; Iris Manor; Robert Oades; Herbert Roeyers; Aribert Rothenberger; Pak Sham; Hans-Christoph Steinhausen; Philip Asherson; Jonna Kuntsi Journal: Psychol Med Date: 2007-05-31 Impact factor: 7.723
Authors: Anita D Barber; Juan A Gallego; Pamela DeRosse; Michael L Birnbaum; Todd Lencz; Sana A Ali; Ashley Moyett; Anil K Malhotra Journal: Biol Psychiatry Cogn Neurosci Neuroimaging Date: 2021-10-30