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Examination of gamma-aminobutyric acid and glutamate-glutamine levels in association with impulsive behavior in adolescent marijuana users.

Punitha Subramaniam, Andrew P Prescot, Erin McGlade, Perry F Renshaw, Deborah A Yurgelun-Todd

Drug and Alcohol Dependence April 1, 2022 DOI: 10.1016/j.drugalcdep.2022.109326 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Observational case-control study Peer reviewed
Sample size 39
Population Adolescent marijuana users (N = 18) and healthy control adolescents (N = 21)
Measures Barratt Impulsivity Scale (BIS-11), metabolite-edited 1H MRS (GABA+, Glx)
Topics Cannabis
Keywords Adolescence Gaba Glx Impulsivity Magnetic resonance spectroscopy
Key findings Adolescent marijuana users had significantly lower tissue-corrected ACC GABA+ levels than healthy controls (p = 0.029), while ACC Glx levels did not differ between groups. Impulsivity scores (motor, non-planning, attention, and total) showed no significant group differences, and impulsivity was not significantly correlated with GABA+ or Glx levels in either group.

Abstract

Adolescent marijuana (MJ) use has been associated with alterations in brain structure and function as well as behavior. Examination of neurochemical correlates such as GABA (gamma-aminobutyric acid) and Glx (glutamate + glutamine) in MJ users remains limited. Impulsivity, identified as a risk factor and consequence of MJ use, has been associated with GABA and Glx levels in healthy and clinical populations. However, this relationship has not been investigated in MJ users. In this study, we examined levels of GABA and Glx in the anterior cingulate cortex (ACC) and its relationship with impulsive behavior in MJ-using adolescents and healthy controls. Healthy control subjects (HC; N = 21) and MJ-using adolescents (N = 18) completed a metabolite-edited 1H MRS exam to measure ACC GABA and Glx levels, a structured clinical interview to assess MJ use, and the Barratt Impulsivity Scale (BIS-11) to evaluate impulsive behavior. Adolescent MJ users had significantly lower tissue-corrected GABA (with macromolecules; GABA+) levels (p = 0.029) compared to HC's. No significant between-group differences were observed in ACC Glx levels. Assessment of impulsive behavior demonstrated no significant between-group differences in motor, non-planning, attention, and total impulsivity scores. Additionally, impulsivity measures and tissue-corrected GABA+ or Glx levels were not significantly correlated in either group. Lower GABA levels in MJ users may indicate alterations in excitatory-inhibitory mechanisms critical for neurodevelopment. Although no significant relationships were observed between impulsive measures and GABA or Glx levels in both groups, further investigations are needed examining the relationship between neurochemical correlates, behavior, and adolescent MJ use.

Comparable studies

Other observational and cohort studies on cannabis, most cited first.

Study Year Design Participants
High-potency cannabis and the risk of psychosis People with first episode of psychosis and healthy controls from the local population 2009 Case-control study n = 454
Ayahuasca-Assisted Therapy for Addiction: Results from a Preliminary Observational Study in Canada Rural aboriginal population 2013 Observational study
Impaired cognitive performance in drug free users of recreational ecstasy (MDMA) Otherwise healthy young people 2000 Observational
Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study Individuals from the general population in Germany aged 14-24 at baseline 2011 Observational cohort n = 1,923
Cannabis-induced psychosis and subsequent schizophrenia-spectrum disorders: follow-up study of 535 incident cases Patients treated for cannabis-induced psychotic symptoms in Denmark between 1994 and... 2005 Observational cohort n = 535

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