Repetitive Transcranial Magnetic Stimulation(rTMS) Ameliorates Inhibitory Deficits In Methamphetamine Addicts

These years,methamphetamine(meth)has been one of the most dominating drugs on the drug market.In some regions,the number of individuals who use it has exceeded total number of individuals who use heroin and cocaine.When individuals can’t stop meth use although it has done great harm to their mental,physical health and social function,they are considered to have been developed meth addiction.Pharmacotherapy and psychotherapy didn’t attain long-lasting ideal effect in the treatment of meth addiction,hence it is indispensable to discover new therapies to treat meth addiction.Urgent craving induced by meth-related cues and declined executive function promote development of meth addiction.Therefore,people usually prevent or treat meth addiction by reducing craving for meth or ameliorate executive function of individuals.Among multiple intervention methods,non-invasive transcranial magnetic stimulation(TMS)gradually drew researchers’ attention out of its convenience.Most of studies which employed repeated transcranial magnetic stimulation techniques(rTMS)to treat drug addiction stimulated left dorsal lateral prefrontal cortex(DLPFC)using high frequency(10HZ)of rTMS and found this protocol could reduce craving for drug and improve cognitive function to some extent,but its effect on craving couldn’t last long and wasn’t efficacious all the time.While a few studies found stimulating right DLPFC with low frequency(1HZ)of rTMS could also reduce craving and this rTMS protocol was also frequently used to treat depressive disorder.Meth addicts often suffer from depression,which is associated with poor inhibitory function.Hence,we infer that a combination therapy which stimulates right DLPFC with low frequency of rTMS(1HZ)first,then stimulates left DLPFC with high frequency of rTMS(10HZ)is more efficacious to reduce craving and ameliorate inhibitory deficits compared with routine therapy that stimulates left DLPFC with high frequency of rTMS(10HZ).In our first research,we initially used questionnaires including PSQI,BDI-II,BAI,BIS-11 scales to test clinical characteristics of meth addicts and found in relative to control group,meth addicts had higher scores in PSQI,BDI-II scales.Then we used go/no-go task to monitor inhibitory function of meth addicts under neutral background or meth-related background.Results showed that in go/no-go task,in relative to control group,meth addicts committed more commission errors in meth-related background,and had shorter reaction time whether in neutral background or in meth-related background.In our second research,two different rTMS protocols,1Hz rTMS of right DLPFC,1Hz rTMS of right DLPFC adding on 10-Hz rTMS of left DLPFC were administered to treat meth addiction.Results showed that meth addicts who received combining therapy committed less no-go errors and had lower BDI-II,PSQI scores in the post-test.Hence,we can draw the conclusion that:(1)Meth addicts are more likely to exhibit depression symptoms and sleep disorders(2)Compared to control group,meth addicts exhibited inhibitory deficits under meth-related background but not under neutral background,and had shorter reaction time in go/no-go task.(3)In relative to routine therapy,combining therapy could ameliorate inhibitory deficits,notably moderated depressive symptoms and to some extent improved sleep quality among meth addicts.