Saturday, June 6, 2009

Scientology's criticism of psychiatry: separating fact from fiction

In my next few posts, I'll lay out my responses to some concerns that scientology expresses about psychiatry.

The first issue I'd like to address is the CoS stance that mental illnesses don't exist, because there are no lab tests or imaging studies we can use to diagnose individual patients. The CoS points out that modern medicine does not have lab tests to diagnose mental illnesses (true). The CoS then makes the illogical leap that lack of a test means lack of a disease (false).

One hundred years ago, medicine did not have lab tests for asthma, gout, or smallpox. Does this mean that those diseases didn't exist or weren't recognized one hundred years ago? No. Like these illnesses, mental illnesses do exist. We can diagnose them, treat them, and quantify how well particular treatments work, even though we don't yet have reliable blood tests for diagnosis.

The practice of medicine is more about talking to patients and examining them than it is about drawing their blood and taking x-rays. 90% of the information needed to make a diagnosis of any kind, from a torn knee ligament to bipolar disorder, can and should be gathered by thorough history and examination. Physicians may use lab tests and other diagnostic studies to obtain more information, but these studies are just part of the larger body of data needed to make a diagnosis and develop a treatment plan.

Psychiatry has solid evidence for alterations in neurologic and endocrine function that correlate with mental illnesses. Here are only a couple of examples:

1) For over thirty years, blood tests such as the cortisol suppression test have shown that depressed patients have different stress response patterns than those of non-depressed subjects.

2) We can demonstrate significant differences in the way glucose is metabolized in the brains of mentally ill patients compared to those of healthy subjects when we look at imaging studies such as functional MRI and PET scans.

Unfortunately, while these differences hold true when comparing groups of healthy controls to groups of people with mental illnesses, our tests are not yet sophisticated enough to use for diagnosis in individual patients.

Psychiatrists are looking forward to the time when we have reliable tests to enhance our clinical care. But even when those tests become available, they won't supplant the importance of history-taking and examination, and we won't need them to prove the existence of mental illness.