Age-related brain volume reductions in amphetamine and cocaine addicts andnormal controls: implications for addiction research

The study evaluated the relationship between age and frontal and temporal l obe volumes in young cohorts of cocaine-dependent (CD), amphetamine-depende nt (Am), and normal control subjects. Ten CD, nine Am, and 16 age- and gend er-matched control subjects underwent magnetic resonance imaging (MRI). The volume of the frontal and temporal lobes was measured from an identically positioned slab of seven contiguous 3-mm-thick coronal images. Follow-up me asures of the gray and white matter subcomponents of these volumes were als o obtained. Both CD and Am groups had a significantly smaller temporal lobe volumes, but only the CD group demonstrated a significantly greater declin e in temporal lobe volume with age (intracranial volume, education, and rac e were controlled for in all statistical analyses). Segmenting the brain re gions into gray and white matter revealed that the negative correlation bet ween age and temporal lobe volume of CD patients was mostly due to a signif icant age-related decline in the gray matter subcomponent. Negative trends between age and gray matter volumes were also observed in the Am and normal groups. In the frontal lobes, age was negatively correlated with gray matt er volume in the control, CD, and Am groups. Unlike the consistent decrease s in gray matter volumes, white matter showed non-significant increases in volume with age. The data suggest that CD patients may have an accelerated age-related decline in temporal lobe gray matter volume and a smaller tempo ral lobe volume compared to normal controls. In the frontal lobe, age-relat ed gray matter volume reductions occur in all three groups. These age-relat ed cortical gray matter volume reductions may be a biological marker for th e risk of addictive behavior, which also decreases with age. (C) 2000 Elsev ier Science Ireland Ltd. All rights reserved.