A Primer on Depression and Bipolar Disorder

II. MOOD DISORDERS AS PHYSICAL ILLNESSES

In this essay we will explore the nature of depression and bipolar disorder as physical illnesses of an organ of the body, known as the brain, which manifest themselves through mental symptoms (see definition on p. 8) in the magnificently complex set of internal experiences we call our mind. I will touch briefly on causes, symptoms, treatment, suicide, impact on family and friends; my focus will be primarily on understanding these aspects of the problem. In addition, I will touch on the issues of self-help and support groups, stigma, public policy, and hope for the future. But the reader must be aware that what I write here is unabashedly devoted to the treatment of the physical aspects of depression and bipolar disorder. The process of healing one's psyche (i.e. one's internal feelings about oneself and the world) after successful medication moves the brain's physiology into the normal range is barely mentioned; it is discussed in my companion essay "Depression and Spiritual Growth" (see Bibliography). Both aspects of the recovery/rebuilding process are critical for sustained growth and wellness of victims of these illnesses.

A. Causes

The ultimate causes of depression and bipolar disorder are not yet known. But over the years a number of hypotheses, theories, or ``models'' have been advanced as possible explanations of these illnesses; some of them have proven to be much more useful in treating the illnesses than others. Some of the earliest work was done by Sigmund Freud, who tried to fit the mood disorders into the framework of ``psychoanalysis'', the talk-therapy technique he invented to treat mental illness. He had some success treating some patients with mild to moderate depression, less success with people who were severely depressed, and essentially no success with people who suffered from bipolar disorder. The latter illness he called a ``psychosis'', i.e. a very severe, and possibly permanent, mental disorder in his scheme of things. The fact that Freud, one of the most brilliant, creative, and insightful of the talk-therapists of all time, got such poor results treating the severe mood disorders is very significant. It is strong evidence that he was using the wrong therapeutic approach; that these illnesses in their most severe forms don't respond to manipulation of our thoughts, but require more direct medical intervention.

Freud's picture of the causes of the mood disorders is quite fanciful and misleading in the light of modern knowledge. But his pioneering methods were essentially the only therapeutic procedures available until the development of useful psychiatric medications starting in the 1950's and onward. Since that time there has been a rapid increase in the number of medications that can be used to treat depression and bipolar disorder effectively. Today, therapy using these medications has largely displaced psychoanalysis for the severe mood disorders. Even though methods based on a psychopharmacological model are often preferred today, results are usually obtained if treatment with medication is combined with one of the modern forms of talk-therapy (usually quite different from Freudian psychoanalysis). Once medication permits the brain to function again within the normal range, it is necessary for almost all victims to go through a carefully-guided, and extensive, period of healing and rebuilding. The fruits of these efforts are frequently stupendous; the victim finds him/herself feeling well, sometimes for the very first time in their lives!

Our basic picture of brain function today is that cognition, memory, and our moods all result from constant passing back and forth of electrical impulses through the extremely complex network of nerve cells that permeates the brain. There is a large body of convincing experimental evidence that this picture is correct, and recently a great deal of theoretical work has allowed researchers to begin to simulate the behavior of this network with computers. If the message-passing process, neurotransmission, is broken, interrupted, diverted to the wrong place, then the transmission of information from one point in the brain to another where it is needed, fails.

In some cases this loss may be inconsequential; in others it may cause a massive failure of the system: loss of memory, misinterpretation of reality or inability to perceive reality, or inappropriate mood. The crucial nexus in the message passing process occurs in a small gap, the synapse, between the extremities of nerve cells, which do not quite touch. The ``firing'' of one cell excites a complex biochemical and biophysical reaction in the synapse, and chemical messengers flood across the synapse from the exciting cell to the receiving cell. The receiving cell, in turn, passes the message on by initiating the same process at the next synapse. If anything goes wrong with this mechanism, if a nerve doesn't fire, if the chemical soup in the synapse is not exactly right, if the receiving cell doesn't respond correctly to the chemical messengers, then message transmission is disrupted. Depending on where and how the interruption occurs, we will experience one or more incorrect psychic phenomena in our minds; if the errors become large, we experience mental illness. In summary, in this model, we say that one suffers from ``mental illness'' when a definite set of physical/chemical disorders in the physical organ we call the brain causes us to experience abnormal and undesirable behavior of the complex phenomenon (which includes awareness, mood, abstract reasoning, thinking, ...) which we call our mind.