Of the 19 chromosomal regions now known to influence depression, only three are found in both genders, according to researchers at the University of Pittsburgh School of Medicine. "Sex-specific genes for recurrent major depression may actually be the rule rather than the exception," says George S. Zubenko, Ph.D., a professor of psychiatry at the university. Scientists knew that genetics accounted for 40 to 70 percent of the risk for developing major depression but could not heretofore confirm that the disease is sex-specific, despite symptomatic gender differences. Women report accompanying anxiety and eating disorders, while men tend to exhibit anti-social behavior and substance-abuse problems.
Another study maintains that depression can be treated or exacerbated by electromagnetic stimulation, depending on the individual. In the dual-brain theory of Fredric Schiffer, M.D., an associate professor of psychiatry at Harvard, one hemisphere hosts a healthy worldview, while the other retains past emotions and trauma that may cause depression. Schiffer found that he could determine the "healthy" hemisphere by covering half the subject's field of vision and asking emotionally charged questions. "Patients experienced amazing personality changes," says Schiffer. "After stimulating one side, they were very negative and immature; after stimulating the other, very positive."