How does alcohol impact the brain

Alcohol affects the brain both while you’re drinking and, with repeated use, over time:

• Weakens judgment and self-control: Alcohol suppresses activity in the prefrontal cortex, which helps with planning and inhibiting impulses. This can make behavior more impulsive and habitual, and impair coordination and speech as intake rises. 1
• Disrupts memory: It suppresses neural networks involved in forming and storing memories. In a blackout, someone may remain awake and active but later have no recollection of what happened. 2 3
• Shifts mood and alertness: Alcohol can initially make mood-related circuits more active, contributing to feeling good or talkative; as drinking continues, those circuits and alertness can become suppressed. 4
• Can reshape circuits with repeated drinking: Regular drinking is associated with stronger connections in circuits involved in habitual behavior and fewer connections in circuits supporting behavioral control. The episode says these changes can improve after a period of abstinence, though long-term heavy drinking may leave lasting effects. 5
• May increase stress and lower mood between drinking episodes: Regular drinking is linked to higher baseline cortisol and greater stress and anxiety when not drinking, alongside diminished mood and well-being. 6
• Is associated with brain tissue loss over time: The episode discusses a large study finding evidence of thinning in the neocortex and other brain regions even among people reporting low-to-moderate regular consumption; it also describes heavier use as clearly harmful to the brain. 7

In short, alcohol can impair control, memory, and coordination in the moment, and repeated consumption can affect brain circuits, mood, stress responses, and brain tissue. 8