Cocaine-dependent individuals showed a significantly greater-than-normal age-related decline in gray matter in prefrontal and temporal regions compared with healthy controls. By contrast, parts of the striatum appeared resistant to age-related volume decline in the cocaine-using group. Enlarged striatal volume has frequently been reported in stimulant-dependent individuals,5, 6 possibly reflecting a marker of reduced dopamine neurotransmission in this dopamine-rich brain region where drugs like cocaine work. Decline in striatal dopamine receptor density has been associated with normal age-related cognitive decline.7 The relative absence of age-related changes in the striatum of cocaine-dependent people may thus reflect another feature of an abnormal brain ageing process.
Could it be related to possible neurotoxicity, or to the long-term effects of dopamine receptor downregulation? Could the effects also be generalizable to those who take dopamine-based ADD medications?
A link to the Letter to the Editor appeared in Molecular Psychiatry to which the ScienceNow article refers:
Cocaine dependence: a fast-track for brain ageing?