Monday, February 21, 2005

Neuroimaging in Psychiatry

The Nytimes has a fascinating article in the Magazine section this week on The Therapeutic Mind Scan

Neuroimaging will soon become commonplace in psychiatric medicine. But should getting a brain scan before getting diagnosed with ADHD or bipolar disorder be a common practice now? I'm of the opinion that we are really not ready for using neuroimaging to diagnose most psychiatric disorders. But, as described in the article, Dr. Daniel G. Amen, (a child and adult psychiatrist based in California) thinks otherwise. His patients get two scans (for $3000 that probably wont be covered by insurance) before he designs a treatment program which may include biofeedback in addition to medication and talk therapy.

I'm all for innovative uses of technology in medicine, and know that in order for new diagnostic tools to be developed, someone has to test them. But I don't think the technology is quite ready for mainstream use. Techniques such as fMRI still need to compare groups of patients--hardly useful for an individual diagnosis. Dr. Amen uses brain scans as a diagnostic tool which is a dangerous practice as there is no "standard" diagnostic criteria for what he does. He makes assumptions that someone is bipolar based on a diagnostic scan, but where is the data that says such a scan is actually indicative of being bipolar?

Admittedly, imaging studies using psychiatric patients is immensely complicated. There are issues of how medication will affect results, and it isn't exactly ethical to keep patients unmedicated for the purpose of scanning them. Until more research is done into the effects of common psychiatric medicine on brain structure and function, it may be hard to conclude that the brain of a bipolar patient who has been on depakote for 10 years will look like the brain of a newly diagnosed patient. And what happens when someone meets the D.S.M. criteria for ADHD but has the brain scan of a schizophrenic? Do you treat the schizophrenia in order to prevent any future problems? Do you wait and see what happens? What about a patient with no psychiatric symptoms with a brain scan indicative of someone with borderline personality disorder? Is it an efficient use of resources to do a scan on someone diagnosed with postpartum depression (especially if they are responding well to treatment)?

I have no doubts that neuroimaging will be commonly used as a diagnostic tool for psychiatric disorders during my medical career. I can only hope that when it does become commonplace, enough studies have been done to make sure it isn't a giant waste of resources, or that it doesn't cause more problems than it solves!