According to meta-analytical data, cannabis intoxication results in small to moderate deficits in various cognitive domains. These acute impairments accord with reported residual impacts, indicating that cannabis-induced detrimental impacts persist beyond acute intake.

• Researchers undertook this meta-review to assess the magnitude of acute and residual impacts of cannabis on cognition in adolescents and adults afforded by meta-analyses as well as to assess quality of evidence.

• By exploring PubMed, PsycINFO, Web of Science and Google Scholar, a total of 10 eligible meta-analyses (71 effects sizes, n = 43 761) were found with evidence ranging from low to moderate quality.

• The most strong evidence was found for verbal learning and memory, and these were most impaired by acute cannabis intoxication that persisted after intoxication passed.

• For executive functioning, small-to-moderate acute and residual adverse impacts were documented.

• Small deficits in inhibitory processes and flexibility as well as small-to-moderate deficits in working memory and decision-making were brought about by cannabis use.

• Evidence concerning processing speed and attention has demonstrated that cannabis use caused small-to-moderate adverse impacts and residual neurocognitive deficits developed in heavy cannabis-using youths.

• Findings revealed no significant difference between cannabis users and non-users on language, and small-to-moderate impacts for simple motor skills.