Methamphetamine and cannabis abuse in adolescence: a quasi-experimental study on specific and long-term neurocognitive effects

Abstract

ObjectivesMethamphetamine abuse affects brain structure and function. Although methamphetamine and cannabis are commonly abused together, few studies have investigated the differential neurocognitive consequences of methamphetamine abuse with or without cannabis. Furthermore, the effects of drug use on the developing adolescent brain remain poorly understood. We compared neurocognitive function between adolescents with ‘pure’ methamphetamine abuse, those with comorbid methamphetamine and cannabis abuse, and healthy controls at baseline and follow-up.MethodsIndividuals residing in the greater Cape Town region, between the ages of 13 and 18 years, were recruited into either Methamphetamine only group (Meth-only; n=10), Methamphetamine and cannabis group (Meth-cann; n=10) or healthy control (n=20) groups using a quasi-experimental design. All participants underwent a comprehensive neurocognitive assessment. Substance-use variables and psychiatric symptom counts were also recorded. A portion of the Meth-only and control participants completed 12-month follow-up assessments.ResultsWhile the Meth-cann group demonstrated widespread neurocognitive deficits at baseline, these deficits were restricted to the self-monitoring domain in the Meth-only group at baseline and at follow-up.ConclusionsMethamphetamine abuse with cannabis abuse is associated with significantly more neurocognitive impairment than methamphetamine abuse alone, and such deficits may be enduring.

Impulsivity predicts poorer improvement in quality of life during early treatment for people with methamphetamine dependence

“…We used the two‐task estimate of IQ (vocabulary and matrix reasoning). This measure has high levels of reliability and validity and has been used previously in individuals with MD .…”

Aspects of Methamphetamine Abuse in Adolescents and Young Adults in a Thuringian County

“…Similarly, the percentage of cannabis users was higher in the methamphetamine group than in the non-user group (OR: 3.27). This may become problematic in the future insofar, as it is known that the combined use of both drugs leads to more extended neurocognitive deficits (Cuzen et al[2]).…”

“…However, with the duration of drug abuse, the risk of neurocognitive disorder (Cuzen et al[2]) and thereby social decline increases (Rommel et al[8]). For the group investigated here, it may be interesting to note that it has been found in animal studies that the susceptibility to neurotoxic effects of amphetamine like drugs is enhanced in the adolescent period (Teixeira Gomes et al[13]).…”

“…With longer duration of abuse addiction will develop, neurocognitive performance, memory, self-monitoring and non-verbal reasoning decrease (Cuzen et al[2]), cardiovascular symptoms, arrhythmia, weight loss besides other symptoms (Courtney and Ray [3]) and psychotic and depressive symptoms may occur (Rusyniak [4]; Glasner-Edwards and Mooney [5]). Methamphetamine has a high addiction liability (Nutt et al[6]).…”

Substance Use, Academic Performance, and Academic Engagement Among High School Seniors

“…A compelling argument for the influence of substance use on academic achievement comes from evidence that substance use is associated with learning and memory deficits that can impede academic performance . Brain imaging studies have found that substance use negatively affects structure and performance in the prefrontal cortex, which is responsible for decision‐making, working memory, and self‐control .…”