There is a body of research observing hypertrophy in basal subcortical structures in stimulant abusing individuals. Chang et al. (2005) found larger putamen and globus pallidus in 50 METH users vs. controls. In that study, METH users had normal cognitive function, and those with smaller striatal structures had poorer cognitive performance and greater cumulative METH usage. Jernigan and Gamst (2005) examined the separate and combined effects of methamphetamine dependence and HIV infection on brain morphology. They found that methamphetamine dependence was associated with basal ganglia and parietal cortex volume increases, with neurocognitive impairment associated with the methamphetamine dependence volume increases (a different pattern of associations from the Chang paper). However, not all studies of METH found enlarged subcortical volumes (see Chang et al.'s, 2007 review). Thompson et al. (2004) reported reduced hippocampal volumes in chronic METH users. More recently, Ersche et al. (2011) found that cocaine users had increased gray matter volumes in the caudate nucleus, and the ventral striatum. Ersche et al. (2012) also reported gray matter medial-temporal lobe and basal ganglia volume increases in both stimulant-dependent individuals and their non-drug abusing siblings.
