Minor Depression Is Effectively Treated with Medication

Minor depression, an underdiagnosed and undertreated subset of major depressive disorder that affects upwards of 15 million Americans*, can be effectively treated with a drug called a selective serotonin reuptake inhibitor (SSRI), according to a multi-center study led by the University of California, San Diego (UCSD) School of Medicine and published in the October 2004 issue of the American Journal of Psychiatry.

“This is especially important since patients with minor depression are not only at risk for significant psychosocial impairment, but for major depressive episodes that can be even more debilitating,” said the study’s lead author, Lewis L. Judd, M.D., professor of psychiatry and chair of the UCSD Department of Psychiatry

He added that unclear categories of illness and diagnosis in the past have led psychiatrists to generally consider minor depression to be a negligible condition that didn’t require any treatment. While some mental health professionals have considered minor depression to be a non-specific variation of normal mood, more recent studies have identified it as a clinically significant medical condition.**

Now, urging that minor depression can and should be treated, Judd said the new study of 162 patients with minor depressive disorder showed that patients given the SSRI fluoxetine (brand name Prozac) over a 12-week period showed significantly greater improvement in mood and psychosocial function as compared to depressed patients receiving a placebo. Several standard psychiatric tests were used to compare the results.***

The National Institute of Mental Health (NIMH) notes that minor depression is a common disorder that can impair a person’s functioning and quality of life, and serve as a serious risk factor for major depression. The difference between major and minor depression is the number of symptoms. Major depressive disorder includes the primary criteria of sadness plus at least five symptoms (such as insomnia, weight loss or gain, low energy, difficulty concentrating, reduction in sexual drive, suicidal ideas and/or behavior, psychomotor slowing, restlessness or irritability, inertia to initiate activity, and persistent physical symptoms, such as headache or digestive disorders, that don’t respond to treatment); minor depression includes the same primary sadness plus one or two additional symptoms.

Judd, a former director of the NIMH and a national expert on depression, said “minor depression is the same as or a less severe variant of major depressive disorder. Significantly, it doesn’t reach the threshold of a major depression. In previous studies, we’ve seen that depressive symptoms wax and wane over an individual’s lifetime, with most depressed patients usually suffering from minor depression more of the time than major depression.”

Because it impairs individuals, Judd and the other leaders of the study recommend treatment for minor depression, especially before it balloons into a major episode. His co-leaders and co-authors of the study were A. John Rush, M.D., University of Texas Southwestern Medical Center, Dallas; and David J. Kupfer, M.D., University of Pittsburgh.

The UCSD study coordinator and co-author of the paper was Mark H. Rapaport, M.D., then a member of the UCSD Department of Psychiatry and currently chair of the Department of Psychiatry at Cedars-Sinai Medical Center, Los Angeles, California. Rapaport noted that the study “is one of the first and largest studies to evaluate the efficacy of an SSRI in the treatment of a well characterized cohort of subjects with minor depression. It has shown us that treating less than major depression with an SSRI does work.”

Additional authors of the study were Kimberly A. Yonkers, M.D., Yale University School of Medicine; Ellen Frank, Ph.D. and Michael E. Thase, M.D., University of Pittsburgh; John M. Plewes, M.D., Pamela J. Schettler, Ph.D., and Gary Tollefson, M.D., Ph.D., Eli Lilly & Co.

The study was funded by an unrestricted investigator-initiated contract from Eli Lilly & Co. and by grants from the NIMH and the Roher Fund of the University of California, San Diego.

* Source = National Institute of Mental Health (NIMH)
The NIMH definition of depression: A depressive disorder is an illness that involves the body, mood, and thoughts. It affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be willed or wished away. People with a depressive illness cannot merely “pull themselves together” and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people who suffer from depression.

** American Journal of Psychiatry 2002, 159:637-643.

*** Inventory of Depressive Symptomatology, Hamilton Depression Rating Scale, Beck Depression Inventory, the Clinical Global Impression severity scale, and the Global Assessment of Functioning Scale.