A study from Cornell University in Ithaca, N.Y., says family turmoil and violence causes stress-induced physical problems in adolescents.
The presence of a responsive, supportive mother, however, appears to reduce the negative physiological changes.
The study, published in the March issue of Developmental Psychology, is the first to look at how maternal responsiveness may protect against cumulative risk.
Psychologist Gary Evans said the findings suggest the physiological toll of coping with multiple stress events is significantly greater than with that of coping with a single event.
The researchers used an index called "allostatic load" to measure stress-induced changes in neuroendocrine hormonal systems, cardiovascular responses and metabolism, which indicate the severity of wear and tear on organs and tissues, the university said.
Copyright 2007 by United Press International