The Effect Of Methadone Maintenance Treatment On Cognitive Functioning In Male Heroin Dependent Patients

Objective Methadone treatment treatment (MMT) is the most frequently used opioidsubstitution treatment in the world, MMT has been shown to be effective in reducingdrug use, and improving psychiatric symptoms, as well as improving overall health,and quality of life. This study will use the Iowa Gambling Task and working memorytests to investigate the characteristics of cognitive functioning impairment in malepatients with heroin dependence in methadone maintenance treatment(MMT).Methods Participants with anxiety or depression had to be excluded.All MMTsubjects were required to have negative urine toxicology screening tests.In study one, A total of45male patients in MMT were compared with matched32health controls on the Iowa Gambling Task.In study two, A total of42heroin dependence patients were compared with31gender-, age-matched healthy persons on working memory tests about visual-space,visual-verbal, visual-face, than compare the accurate rate and reaction time on thesetasks between the two groups.T test, ANOVA and correlated analysis were used to analyze the relationship betweenseveral factors and stigma.Results In study one, Differences between the groups were evaluated by using themean “net disadvantageous score”(number of cards selected from thedisadvantageous decks minus number of cards selected from advantageous decks). The MMP group scored significantly greater than health controls [t(75)=3.89，P<O.01](9.11±19.60，-4.25±10.27respectively)．A2(group)×5(block) ANOVA (analysis ofvariance) on the “net disadvantageous score” from the gambling task revealed asignificant main effect of group (F(1，76)=12.41，P<0.01)．the ANOVA also revealed asignificant main effect of block (F(4，300)=6．87，P<0.01)．The study indicated the “netdisadvantageous score” for MMT subjects was negative correlation to the age ofinitial drug use (r=-0.35，P<0.05). Meanwhile, we find methadone dose and the timeof enrollment MMT did not reveal a significant main effect on decision-making.In study two, The accurate rate of the verbal working memory of the patients is worsethan that of the healthy persons (t(71)=-2.631，P=0.010)(83.10±8.82，88.92±10.04respectively), while the accurate rate of the visual-object and visual-spatial workingmemory did not show any significant differences between the two groups (P>0.05).The difference in reaction time on these tasks between the two groups also did notshowed statistically significant (P>0.05). The time of enrollment MMT did not reveala significant main effect on working memory and executive functions.Conclusion In study one, The study indicated,the deficit of decision making forheroin-dependence patients might be attributed to the dysfunction of the ventromedialprefrontal cortex, and that this effect does not resolve with abstinence, even verylong-term abstinence. Methadone may not get worse this impairment in patients whohave a history of heroin use during maintenance treatment intervention.In study two, The patients showed disproportion impairment on the space, verbal andface working memory, probably because heroin injures the different encephalic region.Methadone may not effect on working memory and executive functions in malepatients who have a history of heroin use during maintenance treatment intervention.