Impaired sustained attention function of heroin abusers in attention switching / 中国神经精神疾病杂志

Objective To investigate the effect of heroin abuse on attention switching. Methods Thirty-six Heroin abusers (33 males, 3 females) and 36 controls (32 males, 4 females) were enrolled in the study. Their cognitive function was tested by using the Switching Task, including Sustained Attention trials and Switching Attention trials. The reaction time and accuracy were recorded separately by the computer. Results The accuracy or reaction times were not signifi-cantly different between Switching Attention trial and Sustained Attention trial in heroin abusers, suggesting a lower Switch Costs value compared to the healthy controls [(19.7 ± 66.8) ms vs. (85.1 ± 92.4) ms]. The healthy controls showed faster reaction speed [Sustained Attention trial (695.3 ± 95.9) ms vs. Switching Attention trial (780.3 ± 93.3) ms, P<0.05] and higher accuracy [Sustained Attention trial (98.0%±2.2%) vs. Switching Attention trial (93.8%±5.0%), P<0.05] under the Sustained Attention trial. Compared with the healthy controls, the heroin abusers showed slower reaction speed [(791.6 ± 74.3) ms vs. (695.3±95.9) ms, P<0.05] and lower accuracy [(92.5%±8.4%) vs. (98.0%±2.2%), P<0.05] in Sus-tained Attention trial, but not in Switching Attention trial. Conclusions The present study has revealed absence of Switch Costs in heroin abusers, which may be related to the damage of heroin abusers in their Sustained Attention function.

Impaired Set-Shifting Ability in Patients with Eating Disorders, Which Is Not Moderated by Their Catechol-O-Methyltransferase Val158Met Genotype

The aim of this study was to examine the set-shifting ability in women with both anorexia nervosa (AN) and bulimia nervosa (BN) and to investigate whether it is contributed by the catechol-O-methyltransferase (COMT) Val158Met genotype. A total of 102 Korean participants-40 women with lifetime AN, 28 women with lifetime BN, and 34 healthy women of comparable age and intelligence quotient- were examined. A neuropsychological battery of tests was applied and blood samples were obtained for COMT Val158Met genotyping. Set-shifting impairments Trail Making Test (TMT, Part B) were found in patients with AN and BN, respectively. Furthermore, the eating disorders were also linked to deficits in attentional mechanisms (TMT, Part A) and motor skills (Finger Tapping Test). Finally, set-shifting and its link to eating disorders were not moderated by COMT Val158Met genotype.