Childhood depression; does it portend asthma and obesity as an adult?
February 22, 2006
By CHRISTINE DELL'AMORE
UPI Consumer Health Correspondent
WASHINGTON, Feb. 21 (UPI) -- Children who are depressed may face serious medical conditions in adulthood, specifically asthma and obesity, a new study suggests. In 20 years of research, scientists found depressed youth under age 17 had an increased risk for asthma and obesity in later years. The researchers looked at adults between ages 20 to 40. "You cannot see these relationships in a single patient at one time," said lead author Gregory Hasler, a researcher at Zurich University Hospital in Switzerland. "This 20-year study shows that healthcare should not be something you do at one point, but something you have to have a long-term perspective on."
Hasler interviewed 591 Swiss adults about their incidence of asthma, how much they weighed, and whether they had experienced depressive symptoms. They were interviewed six times, from 1978 to 1999. The researchers defined obesity as a person having a body mass index over 30. The study appeared Tuesday in the International Journal of Obesity. Scientists have known that asthma, a lung disease that has boomed since the 1980s and afflicts 20 million Americans, is associated with weight gain. Losing weight can often help improve people's asthma symptoms, and conversely, asthma becomes more severe with increased obesity.
But Hasler's research shows that asthma can precede obesity in adulthood, and adds evidence to the argument that obesity does not spur on asthma. However, he warns not to assume that asthma causes obesity. "This finding raises serious concerns about whether this is the whole story," he said. Men depressed as children tended to have higher rates of asthma later on, and women in the study who were depressed were more obese in adulthood. It's a strange association, Hasler said, as most obesity develops early in life, although most people in general gain weight as they grow older.
Hasler could only speculate why these relationships exist. He says it could be genetic: for instance, the neurotransmitters in the brain that control depression also impact obesity and asthma -- leaving open the possibility of a biological problem. In addition, depression in childhood may in fact damage the mechanisms that dictate long-term development of body fat and respiratory function.
The study also did not take into account lifestyle factors such as physical fitness or diet. But it's known that asthma can deter physical fitness, and depression also causes a lack of energy that might prohibit exercise. In addition, asthma drugs are thought to cause weight gain, Hasler said. "We have to be careful how we interpret this," said Kerri Boutelle, a psychologist at the University of Minnesota who studies the relationship between obesity and depression. She pointed out that the depression aspect of the study was retrospective, in the sense that the subjects were asked to reflect, at around age 20, if they were depressed at 11 years old.
Hasler acknowledged this may be a restriction in the study, since the participants in the study were not officially diagnosed with depression, and instead reported their depressive symptoms in interviews. As the prevalence of obesity continues to explode, "this is one more problem associated with obesity that individuals and society will have to deal with," said Richard Atkinson, the president of the American Obesity Association. "As a person develops obesity and asthma, it affects your ability to work, and so it only costs the individual but also society."
Overall, the findings should be a reminder to physicians to emphasize mental health in their checkups, and for parents to be aware that childhood depression is a serious disease that can bring on long-term effects, Hasler said.