No other branch of medicine generates so many critics from within its ranks. The devotion of psychiatrists to their craft impels them. They wrestle daily with its failings  or wince as they cope with those of their colleagues. They address our most complex organ with our weakest tools of reason. Diagnosis has no practical value unless it pinpoints the cause of an illness (see “The Magic of Names” in Chap.9 of “Welcome to the Loony Bin“). Only addressing the cause can remedy disorder. All medicine once depended on descriptive diagnosis, which labels illness in terms of its effects. It amounts to tautology. The patient developed a fever. The doctor diagnosed”fever”. Knowing nothing of cause such as germs, doctors speculated miasmas and practised bleeding. They hastened death. Similarly ignorant, psychiatrists talk of depression and push pills while its rate climbs meteorically parallel to their prescription (see pill pushing).
Effects do not give a reliable guide to cause. Rather, they provide a means to those who mislead (see “Fostering victim mentality”). To reason backwards from the consequent breaks Hume’s law. To take a plain medical example, during the coma caused by a head injury infection produces fever indistinguishable from the brain damage that disorders heat regulation. Compared to fever, depression has an equally inscrutable range of diverse causes extending from genetic predisposition to chance fate. Effects or the descriptive diagnosis cannot tell one from the other. The irrationality invites speculation. In the consulting room it justifies talk of chemical imbalance involving serotonin, delivered as dogma even though science has yet to prove its relevance. Marketing propaganda created the serotonin hypothesis. Similar unreason misleads justice. In the court room reasoning backwards from an effect justifies blaming imagined complaint on the work, or a spouse, or best of all, the boss. In serving these purposes psychiatry turns diagnosis to harm rather than benefit.
In its preamble the authors of DSM-III clearly spelled out the reason why the descriptive approach does not identify cause. But they did not practice what they preached. They invented post-traumatic stress disorder (PTSD), a set of complaints, which they claimed identifies stress-caused illness. Much later the chief designer of DSM-III, Robert Spitzer, condemned the results. The chief designer of DSM-IV, Allen Frances, similarly regretted his own creation. Few recognise that descriptive diagnosis must continue to fail. The textbooks give its flaws little or no mention. Few of the papers that bemoan the weaknesses of psychiatric diagnoses indict it. It has become the ignored elephant in the room (see “Elephantanopia” series). The gaps in the knowledge of cause does not excuse psychiatry. Research has accumulated a great fund that psychiatry ignores, mostly because it does not fit with common prejudice or vanity. Failure demands a radical rethinking of psychiatric theory and practice.
