What does alcohol do to your brain in the long term?
Alcohol harms the brain in multiple ways: from temporary memory blackouts with acute use to lasting cognitive damage from regular drinking during the teenage years. Limit alcohol consumption, especially when you are young.
During a single drinking binge, alcohol can temporarily and completely block the ability to form new memories -- a so-called blackout. This happens because alcohol disrupts the brain's memory centre (the hippocampus). The faster blood alcohol rises, the greater the chance of such a memory gap. Other abilities, such as speech, remain relatively intact in the meantime. Sensitivity to this effect is partly genetically determined.
People who drink heavily on a regular basis as teenagers face a greater risk of lasting damage. The brain is still in full development at that age, and alcohol affects both the prefrontal cortex (responsible for planning, inhibition and decision-making) and the hippocampus (memory and learning). The result is cognitive impairments that remain noticeable into adulthood, such as difficulties with learning. Adolescents are more vulnerable to this damage than adults.
A third mechanism explains why long-term drinking gradually harms the brain: alcohol disrupts the balance between pro-inflammatory and anti-inflammatory signalling substances. This sustains a smouldering inflammation in the brain, which over time damages nerve cells and alters behaviour. The same process also occurs in the liver and lungs.
Three PMIDs (20049223, 32428585, 16573591); the evidence is moderately strong, based in part on animal and mechanistic research. A causal direction is plausible but has not been definitively established for all effects.