Some medical conditions increase risk for developing major depression while others do not

Those who feel sad and lack an interest in regular life activities for at least two weeks and qualify for a diagnosis of minor depression are six times as likely to develop major depression compared to those who don't have these symptoms, according to a longitudinal study on risks for depression.

Most medical conditions do not increase the risk for developing major depression except for those who suffer from a stroke; who are almost ten times as likely to experience a major depression. These findings will be presented at the 113th Annual Convention of the American Psychological Association in Washington, DC.

In a 15-year longitudinal study of 1,634 individuals who were part of the Baltimore Epidemiological Catchment group, researchers Joshua Fogel, Ph.D., of Brooklyn College of CUNY and Daniel E. Ford, M.D., of Johns Hopkins University determined whether a diagnosis of minor depression and/or illness put people at a higher risk for developing major depression.

The participants were examined in 1981 and then again in 1996. Using the Diagnostic and Statistical Manual of Mental Disorders – Fourth Edition (DSM-IV) (6), Fogel and Ford diagnosed minor depression if core symptoms of sadness and/or lack of interest in life activities existed and if at least two but not in total more than five from the above or any of the following non-core symptoms below also existed for two weeks:

1. appetite/weight issues,
2. sleep difficulty,
3. trouble with motor skills,
4. fatigue,
5. guilt,
6. difficulty with concentration and
7. suicidal thoughts. A history of major depression excluded a participant from being diagnosed with minor depression.

Approximately 19 percent of the participants (101 diagnosed with minor depression, 19 went onto to develop major depression) who were diagnosed with minor depression ended up developing major depression over the 15-year time period, according to the study. At baseline, the 18-29 years old and 30-44 years old participants experienced more minor depression than the other age groups. The 45-96 year old participants experienced the least depression and were only 0.23 times as likely to develop major depression. Finally, women were close to twice as likely to develop a major depressive disorder than men.

Individuals who were diagnosed with cancer experienced more minor depression at baseline than those individuals who did not have cancer. Over the 15-year time period, illness like, diabetes, heart problems (like myocardial infarction and hypertension), arthritis, asthma and cancer that are often associated with depression were not associated with major depression in this study.

Many individuals with minor depression either go to their primary care physician or do not seek treatment at all, say the authors. Screening for depression should be considered a part of the examination in any doctors' office, says Dr. Fogel. "This may help address those individuals who suffer from minor depression and provide them help to allow them to receive the appropriate treatment early on. This may help prevent an occurrence of a more severe and debilitating episode of major depressive disorder."