Alcohol and Cannabis Use and the Developing Brain

Purpose of Review

Alcohol and cannabis are the most commonly used substances during adolescence and are typically initiated during this sensitive neurodevelopmental period.

The aim of this review is to provide an overview of the most recent literature focused on understanding how these substances affect the developing brain.

Findings

The effects of alcohol use include:

• widespread decreases in gray matter volume and cortical thickness across time
• slowed white matter growth and poorer integrity
• disrupted network efficiency
• poorer impulse and attentional control, learning, memory, visuospatial processing, and psychomotor speed

Heavy to very heavy cannabis use is associated with:

• decreased subcortical volume and increased frontoparietal cortical thickness
• disrupted functional development
• decreased executive functioning and IQ compared to non-using controls