Neuropsychological Study On Theory Of Mind Cognitive Functioning In Methamphetamine Dependent Patients

Objective Methamphetamine is a highly addictive central nervous system stimulant.Long-term abusers may exhibit varying degrees of brain impairment,such as mental disorders and social cognitive impairment.Mental disorders are mainly schizophrenia-like psychotic symptoms such as hallucinations,delusions,and paranoia.Clinically,nearly a quarter of patients with methamphetamine(METH)dependence has experienced transient psychotic symptoms,which may persist for several months.Theory of Mind(ToM),as the main component of social cognition,is considered to be the basis of emotional intelligence and social functioning,which is appreciated for its role in every day's social interaction.Based on ToM cognitive processing component hypothesis,it includes at least the social-perceptual component and the social-cognitive component.A review of studies on ToM in METH-dependent patients suggests that ToM impairment exists in METH-dependent patients.Therefore,METH-dependent patients with psychosis seems to be an ideal model for studying the relationship between ToM dysfunction and psychosis.However,it is unclear whether the dysfunctions of two ToM components(i.e.,social-perceptual component and social-cognitive component)are associated with their psychosis or not.Also,the acute effect of METH use on these two ToM components has not been investigated.The social-perceptual component and social-cognitive component of ToM are assessed with the Eyes Task(ET)and the Faux pas Task(FPT),respectively.According to these considerations,in study 1,to investigate the difference of Theory of Mind(ToM)processing(especially in social-perceptual component and social-cognitive component)in methamphetamine-dependence patients,and test whether the deficits of ToM is correlated with their psychotic symptoms or not.In study 2,to investigate whetherToM's social perception and social cognition ability of methamphetamine-dependence patients were improved before and after methamphetamine withdrawal or not.Methods 30 METH-dependence patients with psychotic symptoms(METH-P group),31 METH-dependence patients with no psychotic symptoms(METH-NP group)and41 healthy controls(Control group)were recruited.All participants were assessed by Eyes Task and Faux pas Task to test the social-perceptual component and social-cognitive component.The psychotic symptoms of METH-dependence patients were assessed with Brief Psychiatric Rating Scale(BPRS).24 METH-dependence patients with psychotic symptoms(METH-P group)and 23 METH-dependence patients with no psychotic symptoms(METH-NP group)were recruited.All participants were assessed by Eyes Task and Faux pas Task to test the social-perceptual component and social-cognitive component before and after methamphetamine withdrawal,respectively.The psychotic symptoms of METH-dependence patients were assessed with Brief Psychiatric Rating Scale(BPRS)before and after methamphetamine withdrawal.Results Compared with control group,METH-P group and METH-NP group performed poorer in Eyes Task and Faux pas Questions(P<0.05).METH-P group performed poorer than METH-NP group in Eyes Task(P<0.05).There were no statistically significant differences in Faux pas Questions scores between METH-P group and METH-NP group(P>0.05).Eyes Task score of METH-dependence patients was negatively correlated with BPRS positive symptom score,general psychopathological symptom score and total score(P<0.05),but not with BPRS negative symptom score(P>0.05).Multivariate Linear Regression analysis demonstrated that BPRS positive symptom score were correlated with Eyes Task scores of METH-dependence patients(? =-0.415,P=0.001).The positive symptom score,negative symptom score,general psychopathological symptom score and totalscore of BPRS after withdrawal in the METH-P group were lower than those before withdrawal(P<0.05).The general psychopathological symptom score and total score of BPRS in METH-NP group after withdrawal were lower than that before withdrawal(P<0.05).METH-dependence patients with and without psychotic symptoms scored higher in Eyes Task and Faux pas Questions scores after withdrawal than before withdrawal(P< 0.05).Conclusion METH-dependence patients exhibit deficits in both ToM social-perceptual component and ToM social-cognitive component.METH-associated psychosis are related to the deficit in social-perceptual component of ToM.Compared with before withdrawal,Psychiatric symptoms of METH-dependence patients and ToM social-perceptual component and ToM social-cognitive component were improved after methamphetamine withdrawal.