Alcohol Damages the Teen-age Brain
In this report in the June issue of the American Journal of Psychiatry, a special brain scan, called an MRI, was used to measure differences in the sizes of various brain regions in 12 adolescents and young adults who used alcohol excessively, and 24 healthy youngsters who had no drinking problems.
The researchers focused on measuring the size of an area of the brain, the hippocampus, which is known to be sensitive to the effects of alcohol in adults. The hippocampus is associated with learning and memory functions, Clark says. Two hippocampi are found in the brain, one on the right side and the other on the left side.
Both the right and left hippocampi were smaller in teens with drinking problems in comparison with the normal controls. "The difference was fairly substantial, about a 10% difference, which for this area of the brain is a major difference," Clark says. The shrinkage was limited to the hippocampus; no differences were found in other brain areas.
The shrinkage of the hippocampus was greatest in those who began drinking at an early age and in those individuals who were long-time abusers. The authors say the findings suggest that, during adolescence, the hippocampus may be particularly susceptible to the effects of alcohol.
Clark says that studies conducted in animals, as well as on adults with longstanding alcohol use disorders, suggest that alcohol consumption causes the brain damage. Other explanations, however, may be possible. For instance, the brain changes may have preceded the alcohol consumption and contributed to the onset of the alcohol abuse. Or another risk factor may have caused both the drinking behavior and brain changes.
Clark says that at this early stage, it is difficult to say whether brain changes or alcohol abuse come first. He says that longitudinal studies are needed to confirm and expand the findings.
- The brain still is developing during the teen years. A new report suggests drinking alcohol during this time may damage vulnerable areas in the brain. More study is needed to determine the significance of the damage and if it's reversible.
- In the study, doctors took images of teen drinkers' brains and compared them with images from nondrinking peers. Drinkers showed smaller brain regions in charge of memory and learning.
- Drinkers also showed more signs of other mental conditions like depression, conduct disorder, post-traumatic stress disorder, and attention deficit hyperactivity disorder.