RESUMO
BACKGROUND: Many studies have suggested that adolescence is a period of particular vulnerability to neurocognitive effects associated with substance misuse. However, few large studies have measured differences in cognitive performance between chronic cannabis users who started in early adolescence (before age 15) with those who started later. AIMS: To examine the executive functioning of individuals who started chronic cannabis use before age 15 compared with those who started chronic cannabis use after 15 and controls. METHOD: We evaluated the performance of 104 chronic cannabis users (49 early-onset users and 55 late-onset users) and 44 controls who undertook neuropsychological tasks, with a focus on executive functioning. Comparisons involving neuropsychological measures were performed using generalised linear model analysis of variance (ANOVA). RESULTS: The early-onset group showed significantly poorer performance compared with the controls and the late-onset group on tasks assessing sustained attention, impulse control and executive functioning. CONCLUSIONS: Early-onset chronic cannabis users exhibited poorer cognitive performance than controls and late-onset users in executive functioning. Chronic cannabis use, when started before age 15, may have more deleterious effects on neurocognitive functioning.
Assuntos
Desenvolvimento do Adolescente/efeitos dos fármacos , Canabinoides/efeitos adversos , Transtornos Cognitivos/induzido quimicamente , Função Executiva/efeitos dos fármacos , Abuso de Maconha/complicações , Adolescente , Adulto , Fatores Etários , Idade de Início , Análise de Variância , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Canabinoides/administração & dosagem , Criança , Transtornos Cognitivos/epidemiologia , Estudos Transversais , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Abuso de Maconha/epidemiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos/estatística & dados numéricos , Adulto JovemRESUMO
BACKGROUND: Cannabis is the most used illicit drug in the world, and its use has been associated with prefrontal cortex (PFC) dysfunction, including deficits in executive functions (EF). Considering that EF may influence treatment outcome, it would be interesting to have a brief neuropsychological battery to assess EF in chronic cannabis users (CCU). In the present study, the Frontal Assessment Battery (FAB), a brief, easy to use neuropsychological instrument aimed to evaluate EF, was used to evaluate cognitive functioning of CCU. METHODS: We evaluated 107 abstinent CCU with the FAB and compared with 44 controls matched for age, estimated IQ, and years of education. RESULTS: CCU performed poorly as compared to controls (FAB total score = 16.53 vs. 17.09, p < .05). CCU had also a poor performance in the Motor Programming subtest (2.47 vs. 2.73, p < .05). CONCLUSION: This study examined effects of cannabis in executive functioning and showed evidence that the FAB is sensitive to detect EF deficits in early abstinent chronic cannabis users. Clinical significance of these findings remains to be investigated in further longitudinal studies. FAB may be useful as a screening instrument to evaluate the necessity for a complete neuropsychological assessment in this population.
Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/etiologia , Função Executiva/fisiologia , Lobo Frontal/fisiopatologia , Fumar Maconha/fisiopatologia , Adulto , Feminino , Fosfolipases A2 do Grupo II , Humanos , Inibição Psicológica , Idioma , Testes de Linguagem , Masculino , Testes Neuropsicológicos , Autonomia Pessoal , Desempenho Psicomotor/fisiologia , Adulto JovemRESUMO
Substance-dependence is highly associated with executive cognitive function (ECF) impairments. However, considering that it is difficult to assess ECF clinically, the aim of the present study was to examine the feasibility of a brief neuropsychological tool (the Frontal Assessment Battery - FAB) to detect specific ECF impairments in a sample of substance-dependent individuals (SDI). Sixty-two subjects participated in this study. Thirty DSM-IV-diagnosed SDI, after 2weeks of abstinence, and 32 healthy individuals (control group) were evaluated with FAB and other ECF-related tasks: digits forward (DF), digits backward (DB), Stroop Color Word Test (SCWT), and Wisconsin Card Sorting Test (WCST). SDI did not differ from the control group on sociodemographic variables or IQ. However, SDI performed below the controls in DF, DB, and FAB. The SDI were cognitively impaired in 3 of the 6 cognitive domains assessed by the FAB: abstract reasoning, motor programming, and cognitive flexibility. The FAB correlated with DF, SCWT, and WCST. In addition, some neuropsychological measures were correlated with the amount of alcohol, cannabis, and cocaine use. In conclusion, SDI performed more poorly than the comparison group on the FAB and the FAB's results were associated with other ECF-related tasks. The results suggested a negative impact of alcohol, cannabis, and cocaine use on the ECF. The FAB may be useful in assisting professionals as an instrument to screen for ECF-related deficits in SDI.