(NYT) Men who had poor relationships with siblings during childhood are at significantly greater risk for depression in adulthood than those who got along better, a new study has found.

The researchers emphasize that their findings do not mean that a poor childhood relationship with a sibling causes depression, but that the two are strongly associated. Moreover, whether the men's parents did a good or a poor job of raising them seemed to have little effect on their risk of depression.

"Poor parenting may be reflected in poor sibling relationships," said Dr. Robert J. Waldinger, the lead author of the study and an associate professor of psychiatry at Harvard. "But once you've taken account of the quality of sibling relationships, knowing about the quality of parenting doesn't add much information."

The findings are based on an analysis of data from 229 men followed for more than 30 years beginning at age 18 or 19. They were first assessed in the period 1939-42 by internists, psychiatrists, psychologists and anthropologists, and then they completed questionnaires every other year. Researchers also interviewed their parents.