For me, the crucial question of whether depression (unipolar or bipolar) is a disease stems from the somewhat dubious application of the medical model to the theory and practice of psychiatry and psychology. What is the "medical model"? The medical model is the paradigm on which the practice of clinical medicine is founded: Symptoms are seen as manifestations of pathological physiological processes (disease) which are diagnosed and then treated with whatever methods available. The purpose of medical treatment is to eliminate, suppress or control the symptoms of disease. To, as much as possible, reduce suffering and prolong life. Physicians have been faithfully adhering to this honorable paradigm and practice since the time of Hippocrates.
The medical model is a particular way of viewing human suffering, decay, dysfunction and, ultimately, death. It is a paradigm, a lens through which physicians and others perceive certain abnormal or aberrant phenomena like leukemia, diabetes, and now, depression and many other mental disorders. But despite the immense contribution of the medical model in diagnosing and treating disease, its literal application to archetypal human experiences such as depression, psychosis, and anxiety is problematical
There is no denying that those who suffer from severe depression are ill. Depression can be debilitating and, in some cases, deadly. Physical symptoms such as nausea, vomiting, fatigue, chronic pain, diarrhea, insomnia etc. are common concomitants to major depression. "Treatment," to use the medical terminology, is demanded. The real question is what form should that treatment take? The answer to this depends in part on how one understands the etiology or cause of depression and other major mental disorders such as bipolar disorder and psychosis. There are various theories as to the cause of depression, none of which have been unequivocally proven. These causal theories include biological, psychological, social and spiritual explanations. Research indicates the likelihood of at least some genetic predisposition to unipolar and bipolar depression, as well as psychotic disorders such as schizophrenia and schizoaffective disorder. But biological predisposition is not causation. Other (sometimes unrecognized) catalysts are required: loss, stress, isolation, trauma, meaninglessness, frustration, substance abuse, and chronically repressed rage can be, and frequently are, significant if not central contributing factors in these disorders.
The newly discovered evidence that brain scans show a significant signature for bipolar disorder, cited by Dr. Lawlis in his recent post, is yet another phenomenon which, like biochemical theories, begs the classic question of chicken or egg: Could biochemical imbalances or aberrant blood flow patterns in the brain be additional symptoms rather than causes of depression? Physiological manifestations of underlying psychological conditions? Again, as every researcher knows, correlation is not necessarily causation.
But whatever the fundamental cause of depression, clinicians owe it to patients to provide the most aggressive and efficacious treatment methods currently available. The use of psychopharmacology in treating serious depression, despite its drawbacks, has been revolutionary and life-saving. Antidepressants and mood stabilizing drugs do something that psychotherapy cannot: they provide relatively rapid relief of the painful and debilitating symptoms of depression and stabilize otherwise dangerously labile mood swings. Does this prove that depression is primarily a biological disease? Not at all. It only demonstrates that we have fortunately found biochemical means to counteract and control the most acute symptoms of depression: sleep and appetite disturbance, lack of motivation, apathy, depressed or manic moods, anxiety, suicidality, etc. But as Dr. Kramer acknowledges in his recent post, even when the symptoms of depression are mitigated by medication, the underlying depressive condition evidently remains, rendering even medicated patients susceptible to future episodes. More than half of those suffering a first major depressive episode are likely to experience subsequent episodes at some time. The probability of recurrence increases dramatically (90%) after three such episodes. What is this underlying susceptibility? It seems to suggest the presence of something biochemical treatment doesn't resolve. What is this latently persisting vulnerability? It is the depressive core of the personality. It is the figurative heart of the Hydra.
Some mental disorders, including depression, can be likened to the legendary Hydra: a massive mythological monster with nine snake-like heads, each exhaling a lethal poison. Many patients suffer from myriad symptoms—e.g., anxiety, depression, chronic pain, irritable bowel, insomnia, fatigue, headaches, panic attacks, etc.—which, after presumably being pharmacologically vanquished, return with a vengeance. The Greek hero Hercules had to do battle with the deadly Hydra. Luring it from its lair, he started lopping off the Hydra's serpentine heads. But no sooner had he done so, two more appeared in their place. Moreover, the hideous Hydra had one head which was immortal and indestructible. How did Hercules finally defeat the deadly Hydra? First, Hercules cauterized the decapitation cites with fire to prevent more heads from regenerating. Then he buried the immortal head of the Hydra under a massive stone in order to render it harmless. But because this head was immortal, the Hydra could never be completely destroyed. Only attenuated and subdued.
Major depression is a little like the Hydra. You can try pharmaceutically (or even apply electroconvulsive therapy in cases unresponsive to medications) to kill off its symptoms, but they tend to return. Can major depression be defeated? Not without getting to the heart of the Hydra. Depression's roots are, from my own clinical observations, more commonly basically psychological than biochemical--though one clearly affects the other. Often at the very heart of depression is repressed hatred, anger, rage, resentment. Abandonment. Betrayal. Discouragement. Unresolved grief. Meaninglessness. Nihilism. Loss of faith. Without aggressively attacking this psychological, spiritual and emotional core or heart of depression, it cannot be permanently dispatched. Only temporarily suppressed. Which is why pharmaceutical treatment of major depression by itself, while invaluable, is no substitute for real psychotherapy combined with psychopharmacology. Such an ongoing two-pronged attack on the Hydra of depression prevents or mitigates major setbacks, and can keep the dreaded Hydra in check. While the patient may always be biogenetically and/or psychologically predisposed to another depressive episode in the future, such psychotherapeutic treatment can empower the patient to nip such dips in the bud, in effect defeating the Hydra.
Can depression be cured? Should it be treated like any other disease? I think that depends. Some forms of mild to moderate and even severe depression are clearly situational responses to stress, trauma, loss and other life events. These so-called adjustment disorders or even major depressive episodes can be completely recovered from in most cases with adequate treatment, especially psychotherapy. Chronic and profound depression such as dysthymia, recurrent major depressive disorder, cyclothymic and bipolar disorders are more Hydra-like, requiring intensive treatment over prolonged periods of time. But even in these seemingly relatively intractable conditions, penetrating to the heart of the Hydra with psychotherapy combined with pharmacology can reduce both the severity and frequency of depressive and/or hypomanic or manic episodes. By psychotherapeutically improving the person's inter-episodic baseline, the frequency and severity of future episodes can be decreased. But whereas using only medications to fend off this Hydra tends to require increasing dosages and multiple types of drugs to keep it docile, psychotherapy of the sort I suggest in my book can actually reduce dependence on psychotropic medication, as the meaning of the depression and its psychological sources are therapeutically rooted out.
Thus, I submit that depression is not a disease that should be treated in the same way as say, diabetes (which itself is known in many cases to be stress-related). It is a biopsychosocial syndrome requiring far more than pharmacological intervention. The unfortunate fact that most contemporary psychotherapy—including CBT—fails to penetrate to the heart of the Hydra in major unipolar and bipolar depression underscores the desperate need for more effective psychotherapy rather than proving a biological cause for these devastating disorders.