Nassir Ghaemi M.D., M.P.H.

Mood Swings

The Psychological Fallacy

Common sense is wrong in psychopathology.

Posted Aug 09, 2013

Some critics of psychiatry, especially among some sociologists and psychologists and social workers, take a seemingly erudite position that psychiatry simply diagnoses everyone, with conditions like depression, while ignoring the many “causes” in life that produce those symptoms. How many times do we hear the redundant and overworn critique that psychiatry has medicalized every day life?

The critique is not false; it’s more than half-true. We do overpathologize, always have, even before the claims of today’s biologically reductionistic psychiatry: for a century, psychoanalysts overpathologized even though they were anything but biologically reductionistic.

The problem with these critiques and beliefs is that they reflect a deep fallacy in psychology and psychiatry, a far deeper fallacy than the oft-repeated claim of biological reductionism. There is no worse risk for psychology/psychiatry than the psychological fallacy.

How many times has a patient told me, when I asked about depressive or manic symptoms: “Yes, but I was depressed because of x, y, and z”? Or “I get manic when I get really interested in things”?

How many times have I seen mental health clinicians downplay a mood illness diagnosis because they were associated with many psychosocial stressors?

These psychological judgments are basically made based on common sense. But if common sense was enough to explain things, then our patients would have convinced themselves, or been convinced by their friends and family. If a patients crosses the threshold of a clinician’s door, then common sense has failed. No need to keep using it.

What is needed is scientific sense, which is quite different than common sense.

A huge literature on life events and depression shows that the vast majority of depressive episodes occur with a preceding life event that “causes” that depression. What are those life events? Trouble with a spouse, a boss, a child; financial problems; medical illness. So those life events cause depression.


And who doesn’t have those life events? The question should not be why those life events cause depression, but why they don’t cause depression in the 90% of the population that never experiences a severe clinical depressive episode?

Obviously something else is at work. Contrary to all the hopes and wishes of psychologizers, there is such a thing as biology.

The ultimate proofs of the psychological fallacy are the split-brain experiments.

In the 1970s and 80s, some patients with severe epilepsy were treated with corpus collasotomy, so as to prevent spread of seizure activity from one hemisphere to the other, thereby preventing generalized convulsions. This surgery allowed for some interesting neuropsychological research. By showing a picture, like a woman talking on the telephone, to the left visual field of a right-handed split-brain patient, one could test how the patient would report that knowledge. The information could not be transmitted from the right cerebral hemisphere to the left, where the language areas mainly are in right-handed persons. In such a test, the patient would say that she saw something different, like a boy playing with a ball. But if asked to show what she saw, she would pick up a telephone with her left hand. She got the information, but she couldn’t say it.

More important, instead of simply admitting that she couldn’t say it, she made something up! The patient confabulated. That is what the human brain does. As Gazzaniga, the main researcher on this topic said, the brain is a rationalizing machine. We come up with reasons for everything. Sometimes we’re right, sometimes we’re not, and we don’t know which is which in any one case. But the mere fact that we can come up with a coherent, logical, explanation for any experience means quite little.

Of course we can; we always can.

But sometimes common sense explanations are false, especially when something else is at work, like biology, like a disease of the body.  That's why physicians spend about a decade in medical school and specialty training, ostensibly, learning about diseases of the body.  Hence the difference, supposedly, between a psychiatrist and a psychologist.

But this difference, as popular intuition understands, is superficial because psychiatrists, like other mental health professionals, have spent a century denying the relevance of disease models to psychiatry.  Most psychiatrists reject biological disease models (contrary to the assumptions of the public and other clinicians).

Psychosocial life events can influence the timing of a depressive episode, but if someone has repeated depression, biology is the underlying cause of the predisposition to those episodes. That’s why 10% have episodes with the same life event that doesn’t cause episodes in 90%.

That’s why we have to take disease concepts seriously in psychiatry, and we have to accept biology, and not constantly write it off as reductionism. Critics of biological psychiatry are driven by their brains to deny the brain.

Psychological reductionism exists too, and we seem to be biologically hard-wired for it.





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