To the Editor: A major hurdle for clinicians regularly engaging in the critical reductionist approach advocated by Kenneth S. Kendler, M.D. (1), is our own method of diagnosing psychiatric problems, embodied in the DSM-IV-TR. This approach consists of grouping symptoms and applying a label. Purely phenomenalistic, it makes no mention of the underlying causes of those symptoms—whether they are biological, psychological, or social. We must remember that in psychiatry, unlike most other fields of medicine, a diagnosis represents the beginning of the assessment of a patient, not the end. Successful treatment is based on an explanation of the biopsychosocial factors that make up a diagnosis, not only on the diagnosis itself.