Relationship between white matter volume and cognitive performance during adolescence: effects of age, sex and risk for drug use.

Abstract

Familial drug abuse history has been shown to have an impact on cognitive development during adolescence. The present study examined the relationship between white matter volume and cognitive processing speed in adolescents with and without a familial substance abuse history. The sample comprised 33 female and male adolescents stratified by risk (family history positive, FH+) and low-risk (FH-) groups. Gray and white matter volumes were measured by segmenting magnetic resonance imaging (MRI) data. The neurocognitive test battery included tests that assessed processing speed, verbal ability and mental flexibility. Age-related differences in neuropsychological functioning were seen but did not differ by risk group status, although there was some evidence for an age x gender effect. Information processing speed (digit symbol and Stroop word color naming) was correlated significantly with white matter volume; however, this pattern was observed only in FH- females. Cognitive performance and tissue volumes did not differ significantly between risk groups. Age-related differences in neuropsychological functioning were seen that might, in larger samples, prove to be related to risk for substance abuse in adolescents who have not yet initiated drug use.