There is new evidence that depression, obesity and alcohol abuse or dependency are interrelated conditions among young adult women but not men.
Using data collected when young adults were 24, 27 and 30 years of age, a team of University of Washington researchers found that nearly half the sample of 776 young adults tracked during the study met the criteria for one of these conditions at each of these time points.
"The proportion of people with all three of these conditions at any one point is small," said Carolyn McCarty, the lead author of a new study and a UW research associate professor of pediatrics and psychology. "For women there is a great deal of overlap between these common emotional and health problems that span early adulthood. Men may develop one of these conditions but they don't tend to lead another one later on."
"These conditions are major public health problems. They take a toll on families and community and are not subject to quick fixes. It requires a lot of time, money and energy to treat them."
The study found that:
McCarty said the research did not uncover any step-by-step progression from one these disorders to another. However, she said clinicians treating women with one of these conditions should be aware that patients might develop another disorder.
McCarty said there are two possibilities as to why women with alcohol disorder at 24 were more likely to be obese at 27.
"The caloric intake associated with drinking alcohol may increase metabolic processes leading to weight gain. Or there may be an underlying connection to levels of dopamine, a neurotransmitter, in the reward pathway in the brain because the same pathways reward both food and alcohol intake. It also may be that some people substitute food for alcohol, leading to obesity."
She said body image may play a key role in why women who are obese at 27 are more likely to report depression three years later.
"Body image is particularly important for women. There seems to be a transfer that when women feel bad they eat more. That can have devastating effects emotionally and physically. But for men experiencing obesity, the reverse is true, and obesity seems to be protective against depression. It's the so-called 'jolly fat man' theory, which suggests that overweight people are actually happier."
The link between obesity at 27 and subsequent depression at 30 among women may develop as a result of individuals self-medicating themselves.
"People who feel more emotionally down may use alcohol for a quick lift or a short-term boost. The two conditions may be connected by an underlying stress mechanism. Stress is linked to depression, so women under stress potentially eat and drink more," she said.
The study also showed that income has a significant effect on obesity at age 24 and those with higher incomes had a lower risk for weight problem.
McCarty said that finding is not surprising since many of the least nutritional items are inexpensive, and low income areas do not have the same sources of fresh fruits and vegetables that more affluent ones have.
"It costs more to eat well," she said.
McCarty believes that intervention programs are needed and can play a key role in reducing the growing public health burden caused by these conditions.
"Early prevention is important because the sooner we start the more impact we can have. Interventions should include stress management so we can provide young people with tools to cope with situations and emotions. We also need to explore underlying factors that predispose people to these conditions, such as a family background that is not supportive or is toxic."
Data from the study was drawn from the on-going Seattle Social Development Project, which has been tracking the life course of an urban group of now young adults since 1985. The group was almost evenly split between men and women and was 47 percent white, 26 percent African-American, 22 percent Asian American and 5 percent Native American.