Our analysis indicated that changes of dopamine receptors and transporters are moderated by the duration of abstinence .
Our analysis provides strong evidence for a central role of the striatal dopamine system in use of alcohol or opioids .
Use of alcohol , cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs .
The exact pathophysiology of abuse or addiction associated with these sedative substances is not completely understood , but previous research implicates the important role of the striatal dopamine system in the addiction process .
Multiple studies investigated changes in the striatal dopamine systems of users of sedative substances , but currently these results are very heterogeneous .
Therefore , we conducted a meta- analysis of in vivo neuroimaging studies investigating dopaminergic alterations in the striatum of users of alcohol , opioids or cannabis .
Longitudinal changes of dopamine transporters in heroin users during abstinence
Rationale Chronic exposure to heroin results in decreased dopamine transporter levels . Jitai tablets , a traditional Chinese medicine , have been effective at increasing striatal dopamine transporter availability after 6 months of treatment . However , it remains unknown how long the heroin-induced impairment persists and whether dopamine transporter can be normalized following long-term abstinence or treatment . Objectives This study was to evaluate the time course of dopamine transporter changes in heroin users undergoing long-term abstinence and treatment with Jitai tablets for 1 year . Methods Single-photon emission computed tomography using [99mTc]TRODAT-1 was performed on 64 heroin users and 20 healthy subjects to assess striatal dopamine transporter availability at baseline , 3 , 6 , and 12 months . Heroin users were r and omly assigned to treatment with either placebo or Jitai tablets  . Depression and anxiety scores were measured before each imaging session . Results Compared with healthy controls , significant reduction in dopamine transporter availability was found in heroin users at baseline in both the right ( by ∼31.6 % ) and left striatum ( by ∼33.2 % ) . At 6 months , dopamine transporter availability was significantly higher in Jitai tablet-treated group than placebo group in the bilateral striatum ( p < 0.01 ) . At 12 months , dopamine transporter levels in both groups were upregulated substantially from baseline but still not recovered to normal levels in the left striatum ( p < 0.05 ) . Depression and anxiety scores significantly decreased at 3 , 6 , and 12 months ( p < 0.05 ) . Conclusions Our results confirmed that heroin abuse induces pronounced , long-term reduction in dopamine transporter . Treatment with Jitai tablets appears to stimulate recovery
Our analysis indicated that changes of dopamine receptors and transporters are moderated by the duration of abstinence .
Our analysis provides strong evidence for a central role of the striatal dopamine system in use of alcohol or opioids .
Use of alcohol , cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs .
The exact pathophysiology of abuse or addiction associated with these sedative substances is not completely understood , but previous research implicates the important role of the striatal dopamine system in the addiction process .
Multiple studies investigated changes in the striatal dopamine systems of users of sedative substances , but currently these results are very heterogeneous .
Therefore , we conducted a meta- analysis of in vivo neuroimaging studies investigating dopaminergic alterations in the striatum of users of alcohol , opioids or cannabis .