Long-Term Cocaine Self-administration Produces Structural Brain Changes That Correlate With Altered Cognition

Area of Science:

• Neuroscience
• Addiction Research
• Neuroimaging

Background:

• Distinguishing drug effects from pre-existing differences in cocaine users is crucial.
• Longitudinal studies with baseline data are needed to establish causality.

Purpose of the Study:

• To determine if chronic cocaine self-administration causes structural brain changes.
• To assess the causal relationship between cocaine-induced brain changes and cognitive function.

Main Methods:

• Longitudinal anatomical magnetic resonance imaging (MRI) in rhesus macaques.
• Neurocognitive assessments (cognitive flexibility, working memory) before and after 12 months of cocaine or water self-administration.
• MRI scans after 2 years of forced abstinence.

Main Results:

• Cocaine use led to gray matter density (GMD) decreases in orbitofrontal cortex, insula, amygdala, and temporal cortex.
• Increased GMD was observed in the caudate putamen.
• GMD changes correlated with cognitive impairments in specific cortical regions.
• Some GMD alterations persisted after prolonged abstinence.

Conclusions:

• Cocaine use causally alters regional GMD.
• These structural changes appear to drive cognitive impairments.
• Persistent GMD changes may indicate a risk for relapse.