Mary Vieten, Ph.D., ABPP

A recent study claiming that brain scans can help predict a person's response to SSRI drug treatment for PTSD is flawed from the start.

Brain scans to diagnose or determine the treatment of poorly defined constructs with very little inter-rater reliability and as little validity (e.g., all mental illness diagnoses) is yet another example of scientists who are forging ahead with sophisticated research that is based on the assumption that “mental illnesses” are in fact real illnesses and that they are discrete, scientifically identifiable diagnoses.

The fact is, anyone who was placed in the PTSD positive group in this study was put into that group in the exact same way every “mental illness” patient gets categorized, labeled, branded: some combination of interview (or symptom checklist) and self report.  Nothing objective, scientific, or medical is involved.  Hundreds of ways in which this could go wrong.  Every participant could have ended up in another diagnostic category, or no category at all.

Science isn’t supposed to work this way.  Variables should be clearly, independently identifiable.  The streptococci bacteria, the cancer cell, the fracture, death: no issues with reliability or validity here.  The problem is that we are pathologizing undesirable aspects of the  normal range of human experience, and pretending we have identified real illness that we can see on a brain scan.  An intelligent observer should be torn between the scandal of resources being used in this way, and the serious lack of critical thinking skills among our research scientists.