Effects of smoking abstinence on reaction time variability in smokers with and without ADHD: an ex-Gaussian analysis.
Smoking abstinence differentially affects cognitive functioning in smokers with ADHD, compared to non-ADHD smokers. Alternative approaches for analyzing reaction time data from these tasks may further elucidate important group differences. Adults smoking > or = 15 cigarettes with (n=12) or without (n=14) a diagnosis of ADHD completed a continuous performance task (CPT) during two sessions under two separate laboratory conditions--a 'Satiated' condition wherein participants smoked up to and during the session; and an 'Abstinent' condition, in which participants were abstinent overnight and during the session. Reaction time (RT) distributions from the CPT were modeled to fit an ex-Gaussian distribution. The indicator of central tendency for RT from the normal component of the RT distribution (mu) showed a main effect of Group (ADHD < Control) and a Group x Session interaction (ADHD group RTs decreased when abstinent). RT standard deviation for the normal component of the distribution (sigma) showed no effects. The ex-Gaussian parameter tau, which describes the mean and standard deviation of the non-normal component of the distribution, showed significant effects of session (Abstinent > Satiated), Group x Session interaction (ADHD increased significantly under Abstinent condition compared to Control), and a trend toward a main effect of Group (ADHD > Control). Alternative approaches to analyzing RT data provide a more detailed description of the effects of smoking abstinence in ADHD and non-ADHD smokers and results differ from analyses using more traditional approaches. These findings have implications for understanding the neuropsychopharmacology of nicotine and nicotine withdrawal.
Kollins
Scott H
SH
Department of Psychiatry, Duke ADHD Program, 718 Rutherford Street, Durham, NC 27705, United States. Kolli001@mc.duke.edu
McClernon
F Joseph
FJ
Epstein
Jeff N
JN
D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000503:physiopathology* / Q000523:psychology; D006801:Humans; D016011:Normal Distribution; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time; D012907:Smoking / Q000503:physiopathology* / Q000523:psychology; D016540:Smoking Cessation / Q000523:psychology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology / Q000523:psychology