Long-term drug use causes structural shrinkage in brain regions critical for decision-making and memory.

Chronic use of substances like opioids, cocaine, and methamphetamine can physically reduce the size of the prefrontal cortex and hippocampus. The prefrontal cortex governs rational thinking, impulse control, and decision-making, while the hippocampus is essential for forming new memories. Shrinkage in these areas impairs a person’s ability to regulate behavior and retain information, making it harder to resist cravings or learn new habits. Brain imaging studies have repeatedly shown these changes, linking them to the cognitive difficulties seen in long-term users.