Psychotic symptoms—delusions, hallucinations, paranoia, thought disorder—are mostly attributed now to aberrations in brain structure and function. The iconic "chemical imbalance," thought to be a consequence of wrongly wired neural circuits and faulty receptor activity, is seen as an essential component in the distortions of thinking, feeling, and behavior that are different enough from the norm to merit the designation "psychotic."
The physiologic derangement that sometimes occurs in those who use drugs such as amphetamines, lysergic acid diethylamide (LSD), and phencyclidine is a known cause of psychosis. So, too, are certain derangements of electrolyte, endocrine, and metabolic functions. Biologic psychiatry, the dominant paradigm in mental health now, has extrapolated this association between a known, and sometimes measurable, chemical imbalance and psychosis to explain delusions and hallucinations of unknown pathogenesis that are part and parcel of some mental disorders.1 In this model, the mind becomes a somewhat passive theater of the brain's chemical imbalance, ineluctably producing pathologic thought, emotion, and behavior.
Not so fast. The following story about an elderly woman whose behavior would be considered paranoid and delusional by any standard challenges us to reconsider the need to invoke a chemical imbalance to explain all psychotic symptoms.
A willed paranoid delusion?
"Mrs K," who is 95 years old, lives alone in a ranch-style house in a rural suburb. On most days during the spring, summer, and fall when the weather is good, Mrs K works outdoors in the garden. Last fall, she raked 40 bags of leaves. During the winter, when a snowfall is 6 inches or less, Mrs K shovels the driveway out to the road; after heavier accumulations of snow, she calls in someone with a plow. She never complains about having to cope with the long, cold winters.
Mrs K pays her bills and never overdraws her checking account. She prefers to spend most of her time alone and encourages only occasional, short visits from family members. She has no friends and wants none, even though neighbors occasionally make overtures to her. She keeps up with the outside world by watching the news on cable television. In 1986, Mrs K's husband died suddenly of heart failure. She has never shown any sign of mourning and, in fact, seemed rejuvenated by her husband's death. Although Mrs K values life in her advancing years and takes good care of herself, she has made it clear that she is not afraid to die.
Mrs K has a good quality of life and can still do many of the things that were always important to her. Her sense of the world is largely intact. She appears thin and frail, but for a nonagenarian, her health is good. Her close vision has deteriorated and she can no longer sew, but beyond 6 feet she sees well. She takes 81 mg of aspirin every other day and receives monthly subcutaneous injections of vitamin B12 and folic acid. Mrs K has had occasional chest pains since her mid-80s, which her doctor attributes to angina. Sometime after that she was found to have atrial fibrillation. Her only prescription medications are diltiazem and clopidogrel.