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November 16, 1998

New study shows roots of depression go deep

By Jennifer McNulty

When psychologist Per Gjerde began looking for early-childhood roots of adult depression, he didn't expect to find much. After all, the passage from childhood to adulthood is so complex and varied it seemed unlikely that any precursors evident during the toddler years would hold up through adolescence and into young adulthood.

Per Gjerde

But he was wrong. His findings were surprisingly robust, particularly for boys, who exhibit distinct personality characteristics even at age three that correlate strongly with depression later in life. For girls, too, a path toward depression emerges early on, although that path appears to be more complicated and more difficult to understand.

Intelligence turns out to be a key indicator for both sexes, said Gjerde, whose findings are based on an in-depth study of 100 individuals from the age of three to 23.

At age three, boys who exhibit less intelligence, inability to control their impulses, and a high degree of antagonism toward others appear to be at greater risk of experiencing chronic depressive symptoms later in life, said Gjerde. "There's an anger component toward other children," he noted.

Antagonistic and impulsive behavior remains evident at the age of 14, when other traits include independence, assertiveness, behaving in a stereotypically "boyish" way, being talkative, and being unable to delay gratification. At age 23, the inability to delay gratification and attempts to stretch limits combine with rebellious behavior, hostility toward others, and unpredictable behavior, although other traits also seemed to be emerging, including a greater sense of vulnerability, and sometimes despair.

The path toward adult depression appears to be quite well-defined for boys, said Gjerde. "If we know how this boy is at three, we can say with considerable certainty how he'll be at 18 or 23," he noted.

By contrast, little boys who did not go on to experience depression were highly intelligent, emotionally expressive, verbally fluent, and curious. At 14, the youths valued intellectual matters, had high aspirations for themselves, and were dependable, responsible people, said Gjerde. By the age of 23, these young men were cheerful, gregarious, talkative, socially poised, and had the capacity for close relationships.

Gjerde's research is based on one of psychology's most highly regarded longitudinal studies. Begun in 1968 at UC Berkeley by Jack and Jeanne Block, the study has traced the lives of about 100 young adults since the age of three. Gjerde joined the research project in 1979; it is currently located at UCSC.

Participants in the ongoing study have been evaluated eight times over the years, allowing researchers to look back in time for clues of behaviors that might appear later. An assessment at age 32 is currently under way.

For girls, the pathway to depression appears to be more complex. "It's much more difficult to make a direct prediction for girls in areas of adjustment," said Gjerde. "As a preschooler, a girl may have seemed very well adjusted and promising, but at 18 she came back as a very brittle, neurotic person. Something breaks down in adolescence. The transition through puberty seems particularly difficult for girls."

At the age of three, the traits that appeared in girls who later suffered symptoms of depression were traits that society tends to value, such as independence, verbal ability, competence, self-reliance, confidence, and intelligence. By 14, the girls had become critical, moody, and concerned with their own adequacy, although they remained fairly autonomous and smart. Nine years later, the signals were even more straightforward: The young women tended to be self-defeating, distrustful of people, hostile toward others, and unable to modify their own typical behavior to accommodate new circumstances.

"You don't find the same pattern of angry, antagonistic, impulsive behavior in girls that you see in boys," said Gjerde, adding that several studies have shown that men and women react differently to depression. "Men tend to act outwardly on the world, while women tend to turn inward, become introspective, and ruminate about their problems."

Unlocking the secrets of depression in girls is important because twice as many girls as boys experience depression after puberty, a gap that persists at least through the middle adult years, said Gjerde.

Rumination may be a key. "It's good to introspect, but once introspection becomes excessive, something you can't escape from, it may lead to rumination," explained Gjerde. "Rumination makes things worse, and it may, in combination with high intelligence, be a risk factor for depression in girls, just like low intelligence appears to be a risk factor for boys."

Like excessive introspection, intelligence seems to have its downside. "If you're very bright, you see things and are able to empathize with others in a way that less intelligent people do not," said Gjerde. "Intelligence is not necessarily only good. The correlation between high intelligence and happiness is far from perfect."

International media coverage of this study on depression, including reports on CNN and by the Associated Press, prompted many people to write Gjerde about their own experiences. Particularly compelling are numerous e-mail messages from 15- and 16-year-old girls struggling with their own feelings of depression, including young, intelligent girls who wrote of "'having to deny my nature, having to hide my nature,'" he said.

"It may be that society's gender-role prescriptions for girls become problematic during adolescence," he said. "It may be that smart, intelligent girls are not received well. We may not be as enlightened as we like to think."

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