To Emily Dickinson, it was “fixed melancholy.” To essayist George Santayana, it was “rage spread thin.” The turns of phrase conjure different emotions, but these two writers were describing the same disorder: depression. The variance is more than a matter of literary or philosophical differences; it also reflects the fact that one was a woman, the other a man.
Therapists have long known that men and women experience mental illness differently. Yet when clinicians designed the Diagnostic and Statistical Manual of Mental Disorders, the guidebook they use to diagnose psychiatric maladies, they purposely made the disease descriptions gender-neutral. Today evidence is mounting that in turning a blind eye to gender, clinicians are doing their patients a disservice. In fact, as more researchers investigate sex differences in depression and other mental illnesses, the inescapable conclusion is that gender influences every aspect of these disorders—from the symptoms patients experience to their response to medication to the course of a disorder throughout a person's life.
Depression is the most common psychiatric disorder in the world, affecting more than 150 million people, according to the World Health Organization, or roughly 4 percent of the global adult population. In the U.S., the incidence is higher—48 million people, or 19 percent of the adult population, as reported in a recent survey conducted by the Centers for Disease Control and Prevention. (The higher U.S. figure may be linked in part to greater awareness of the disorder.)
The most obvious difference between male and female depression is prevalence. Population studies indicate that women are about twice as likely to be afflicted as men. As a result, research on depression and gender has historically focused on why women are more vulnerable to the ailment—even though, for reasons mainly to do with convenience, most studies of antidepressant drugs have recruited only male subjects.
More recently, however, researchers have started to study the deeper dissimilarities. Perhaps the most important of these, and the one most frequently misunderstood by people of both genders, is the difference in symptoms expressed by women and men. For women, the primary emotion of depression is usually sadness. For men, it is more typically anger or irritability, often coupled with recklessness. As a result, many women and men, including depressed men, mistake male depression for general frustration and restlessness rather than a serious disorder in need of intervention. Depressed men are also much less likely to seek help than depressed women, and they are much more likely to kill themselves. According to the CDC, the male-to-female suicide ratio is four to one.
The big question is whether the variations are a matter of biology or culture. Some researchers believe the brain chemistry of depression is the same in men and women but that social norms do not let men express sadness, so they often have difficulty articulating their symptoms. “They'll say, ‘I'm not getting as much done,’ or ‘I keep getting into fights with my girlfriend,’ rather than ‘I'm sad,’” says Sam V. Cochran, director of counseling at the University of Iowa and author of books on male psychology. “But once we get past that, the symptoms are pretty much the same as for the female patients.”
Cochran and others who emphasize the importance of cultural influences are increasingly in the minority. An ever growing body of evidence suggests that biology sets men and women apart in ways that have real consequences for mood and behavior—including their susceptibility to depression and other psychiatric disorders. Perhaps not surprisingly, these differences emerge from the very substances that define gender in the first place: sex hormones. Understanding the effects of these hormones on the brain may be the only way to make sure that every depressed patient gets the right treatment.