Depression is increasing in industrialized countries, and no one is sure why. The U.S. Centers for Disease Control estimates that one in 10 American adults is suffering from depression; in Great Britain, government estimates are as high as one in six. This is roughly triple the rates that occurred in 1992.
The question is whether more people are actually depressed or if depression is simply being diagnosed more often. An estimated 30 million Americans are taking antidepressant drugs, and 95% received them through their family doctors, not psychiatrists.
Some experts like Dr. Jerome Wakefield of the New York University School of Social Work believe that depression is being overly diagnosed. Even television advertisements for antidepressant drugs may be playing a role in the phenomenon.
"We have direct-to consumer advertising, where pharmaceutical manufacturers can tell the public, ‘If you experience sadness, you’re unhappy with your child and your spouse, you’re not yourself for a period of time, you should see a physician, you may have X disorder," he told CBS news. "… (This) reshapes our cultural view of what is normal range emotion that individuals can handle and what needs to get meditation or needs to get professional help. We are getting to the point where it is no longer acceptable to sad."
Clinical depression, according to Dr. Wakefield, happens when "something goes wrong with people’s ability to process loss, or it goes wrong way or they are just generating sadness in an unstoppable fashion that immobilizes them."
The official criteria for depression, as spelled out in the current edition of the Diagnostic and Statistical Manual of Mental Disorders, requires that a person has five of the following symptoms for at least two weeks: depressed mood most of the day, diminished pleasure, sleep problems, psychomotor agitation or retardation most of the day, feelings of worthlessness, fatigue, diminished ability to think or concentrate, and thoughts of death. These symptoms must cause impairment in one’s everyday functioning and must not be due to bereavement or drugs.
Clinical depression as described above or its cousin, post-traumatic stress syndrome (PTSS), can last for years and have a debilitating effect on the human body. In fact, the latest theory is that depression is a disease of the body that occurs on the cellular level, which can lead to premature aging and early onset of stroke, dementia, heart disease, and diabetes. A study from Duke University using brain scans of elderly people found that those with depression show faster than average age-related loss of brain volume.
Both depression and PTSS may affect the shortening of telomere length, a key factor in aging. Telomeres are protective coverings at the end of chromosomes that shrink and finally disappear as people age.
A recent study from the University of California in Los Angeles compared the telomere lengths of 43 adults with PTSS and 47 healthy controls, and found shorter telomere length in the PTSS group. Having PTSS meant 4.5 years of accelerated aging in participants whose average age was about 30 years old, according to the study published in Biological Psychiatry.
The good news is that if you decrease stress in your life, your telomere lengths may start to lengthen. A study from University of California in San Francisco found patients with prostate cancer who made positive changes in their life styles not only improved telomere length but also had lower levels of cholesterol and psychological distress.