Q. Would you please clarify an apparent contradiction for me? When I research anti-depressants, I read that the cause of depression is thought to be a low level of Serotonin in the brain. But I also read that the suggested length of treatment with anti-depressant medications is only 6 - 12 months. If the depression is caused by a chemical imbalance, why wouldn't I need to be on it for the rest of my life?

A. A very good question with a number of politically correct answers and not politically correct answers. I will give you a sampling of both. There is actually little data to suggest that folks can ever "come off" of antidepressants and stay well. What the data does show; is that stopping antidepressants will not result in an immediate return of depression for most folks. Over time, however, the majority relapse. This must also be viewed within the context of the illness. Depression, like asthma or diabetes. exists along a spectrum. Some folks have one episode, and others are constantly depressed. More often than not, patients fall somewhere in between these two extremes. If you have your first ever episode at 35 after the death of a child or mate, your chances of recurrence are less than those of someone who has been depressed continuously since age 15 or less than someone who has had four episodes since age 15.

The current strategy is to treat a first episode for 12 months. If it passes, taper the medications and follow the patient. If the episode recurs, treat for two years and then try to taper the medications. If the person has been depressed three or more times, most of us plan on treating for life.

The illness is not a serotonin deficiency. Serotonin is just something we can measure (in a research setting) that goes up or down with the illness. We are all looking for the cause and better treatments.