HighlightsA broad range of domains of neuropsychological performance are significantly impaired in studies which have compared  methadone population s with the healthy controls .
However low power , poor quality and heterogenous population s limit the interpretation of these results .Short term ( less than 1 year ) abstinent groups , when compared with methadone groups , still exhibited cognitive impairments but results are inconclusive .
It is still not clear what the role of global sedative effects of opioids such as methadone have on cognitive impairment .
Only higher quality longitudinal studies using ecologically valid cognitive tests , in well‐defined population groups can address this question .Methadone population s present with a broad range of neuropsychological impairment when compared with healthy controls .
Results : Data from a total cohort of 1063 CM , 412 AP and 879 HP participants , from 23 independent studies  indicate global impairments in neurocognitive function in CM relative to HP participants .
Conclusion : Method ological issues such as small sample sizes , heterogeneity and poor quality limited the interpretation of the results and does not address whether the observed impairments reflect co‐morbid functioning , methadone‐related sedation and /or other factors .
Introduction : There is a presumption that neurocognition is commonly impaired in chronic methadone exposed individuals ( CM ) when compared with healthy controls ( HP ) .
Additionally , it remains unclear if short term ( < 1 year ) abstinence ( AP ) is associated with an altered cognitive profile when compared with CM .
Maintenance therapy with synthetic opioids and driving aptitude
AIMS To assess the influence of methadone and buprenorphine maintenance treatment on the driving aptitude of opioid-dependent patients . DESIGN Prospect i ve , open label , outpatient maintenance , single-blind ( investigator ) study . PARTICIPANTS AND SETTING Thirty opioid-dependent patients maintained on either methadone or buprenorphine were recruited from the drug-addiction outpatient clinic in Vienna . MEASUREMENTS The traffic-relevant performance dimensions of the participants were assessed 22 h after receiving synthetic opioid maintenance therapy  , by a series of seven tests constituting the Act & React Test System ( ART ) 2020 St and ard test battery , developed by the Austrian Road Safety Board ( ARSB ) . To test for additional consumption of illicit substances , blood and urine sample s were taken at the beginning of the tests . FINDINGS The patient group only differed from control subjects in two of the ART 2020 St and ard tests . During a task to test the subject 's attention under monotonous circumstances ( Q1 test ) , patients had a significantly greater number of reactions ( p = 0.027 ) and a significantly higher percentage of incorrect reactions than control subjects . When driving in a dynamic environment ( DR2 test ) patients had a significantly longer mean decision time ( p = 0.029 ) and mean reaction time ( p = 0.009 ) compared with control subjects . Interestingly , when separated into treatment groups , the mean decision and reaction times of buprenorphine-maintained patients in the DR2 test did not differ from controls , whereas patients maintained on methadone showed significantly prolonged mean decision ( p = 0.009 ) and reaction times ( p = 0.004 ) . In this same test , patients who had consumed additional illicit drugs had a longer mean reaction time compared with control subjects ( p = 0.036 ) . CONCLUSION The synthetic opioid-maintained subjects investigated in the current study did not differ significantly in comparison to healthy controls in the majority of the ART 2020 St and ard tests
HighlightsA broad range of domains of neuropsychological performance are significantly impaired in studies which have compared  methadone population s with the healthy controls .
However low power , poor quality and heterogenous population s limit the interpretation of these results .Short term ( less than 1 year ) abstinent groups , when compared with methadone groups , still exhibited cognitive impairments but results are inconclusive .
It is still not clear what the role of global sedative effects of opioids such as methadone have on cognitive impairment .
Only higher quality longitudinal studies using ecologically valid cognitive tests , in well‐defined population groups can address this question .Methadone population s present with a broad range of neuropsychological impairment when compared with healthy controls .
Results : Data from a total cohort of 1063 CM , 412 AP and 879 HP participants , from 23 independent studies  indicate global impairments in neurocognitive function in CM relative to HP participants .
Conclusion : Method ological issues such as small sample sizes , heterogeneity and poor quality limited the interpretation of the results and does not address whether the observed impairments reflect co‐morbid functioning , methadone‐related sedation and /or other factors .
Introduction : There is a presumption that neurocognition is commonly impaired in chronic methadone exposed individuals ( CM ) when compared with healthy controls ( HP ) .
Additionally , it remains unclear if short term ( < 1 year ) abstinence ( AP ) is associated with an altered cognitive profile when compared with CM .