Adolescence and young adulthood are developmental stages of transition during which humans, as well as members of many other species, mature physically and behaviorally into their adult state. Adolescents and young adults need to acquire the physical and behavioural skills that will allow them to live independently of their parents, sustain themselves, and reproduce. This period is marked by more frequent and sophisticated social interactions with peers, exploration of new situations and behaviours, and an increased willingness to take risks. In humans, this often involves the initiation of alcohol and other drug use.
At the same time, the brain undergoes considerable structural and functional changes, at least in part in response to the individual’s many new experiences. Connections among nerve cells (neurons) in the brain can change based on which neurons or groups of neurons are regularly stimulated, a characteristic known as plasticity.
This natural process serves to eliminate unnecessary or unused nerve cell connections,1 allowing the survival of only those neurons that make meaningful contacts with other neurons. (1 Human infants are born with far more neurons than are found in the adult brain. Based on a child’s interactions with the environment, the neurons and connections that are most meaningful can be selected.) This winnowing of neurons is influenced by, among other factors, the adolescent’s interactions with and experiences in the outside world.
Adolescence is such a critical phase in brain development that the actions of alcohol and other drugs on the brain can be assumed to have a particularly profound impact during this developmental period.
New research indicates that even moderate drinking by adolescents on a regular basis can cause potentially lasting changes to the part of the brain that affects memory.
Much of the previous research focused on behavioral effects of alcohol consumption. The new study looked at long-term effects of “intermittent” drinking on the circuitry of an adolescent brain.
As a society, we think that adolescence is over once someone hits 18. But from a neuroscientist’s perspective, the brain isn’t fully developed until age 25 and can exhibit these negative effects of alcohol consumption until then, says Dr. Swartzwelder lead scintist and professor of psychiatry at Duke University in Durham, N.C.
Adolescence is a unique stage of brain development which is particularly sensitive to the disrupting effects of alcohol. One brain area that seems to be particularly affected by adolescent alcohol consumption is the hippocampus, which plays a role in numerous cognitive functions, including learning and memory.
The study published recently in the journal Alcoholism: Clinical & Experimental Research Alcohol’s affects on adolescent brain
