Minor developmental delays early in life, like beginning to walk later than average, may forecast alcoholism, according to a new study. The authors suggest that such problems with early childhood brain development may in fact contribute to the disease.
The brain's cerebellum plays a crucial role in motor development and the control of fine, coordinated movements such as walking and playing musical instruments. Some researchers have proposed that the region is also involved in impulse control and that a dysfunctional cerebellum may therefore predispose to addiction. This theory led pharmacologist Ann Manzardo of the University of Kansas Medical Center in Kansas City, Kansas, to ask whether variations in early motor performance might predict alcoholism later in life.
To test the theory, Manzardo's team analyzed data from a well-known Danish alcoholism study that followed 330 baby boys--two thirds of whom had alcoholic fathers--through their 40s. Looking at motor development and the frequency of alcoholism in the subjects at age 30, Manzardo and her team discovered that 77% of the alcoholics had not yet been able to walk at 12 months of age, compared to 43% of nonalcoholics. Because the cerebellum is involved in motor development, Manzardo says the region may be an additional marker for alcoholic tendencies. As such, she says, "we need to focus more on early childhood brain development to see if there are contributing factors to the development of alcoholism." The team reports its findings this month in the journal Alcoholism: Clinical & Experimental Research.
The study is important because "the cerebellum has been overlooked as playing a possible role in the development of alcoholism," says Marc Schuckit, a psychiatrist at San Diego Veterans hospital and University of California (UC), San Diego. But according to Mary O'Connor, a psychologist specializing in prenatal alcohol exposure at the UC, Los Angeles School of Medicine, the study does not conclusively implicate the cerebellum in alcoholism. The motor defects, she says, may just be a sign of a general developmental delay that could be caused by a variety of factors.