Sometimes I think there’s some sort of secret competition going on with American mental health professionals to see who can diagnose mental illness in the youngest child.
There’s no doubt that young children can become disturbed, but many clinicians doubt that mental disorder manifests itself in the same way in children.
In some cases it hardly seems to manifest at all. For example, psychosis very rarely occurs in children from 10-16 years, and is almost unknown at younger ages.
Although no-one is quite sure why, the typical age of onset for psychosis is about 18-30 years.
Almost all psychiatric diagnosis is made on the basis of a detailed interview in which the patient describes their mental state, guided by careful questioning from the clinician.
Like other diagnoses, the diagnostic criteria for adult PTSD has many points which could only be discovered through interview.
Therefore, the diagnosis of any psychiatric disorder in a pre-verbal child or child with developing language skills would have to be made on very broad criteria.
So broad, some would say, to be highly unreliable or of doubtful validity.
The author of the case study, psychologist Aletha Solter, admits that the adult criteria would be inapplicable, and instead applies diagnostic criteria for pre-verbal children developed by charity Zero to Three (intro online as pdf).
However, despite the fact that these diagnostic criteria do not rely on verbal report, it’s still not clear whether they represent a reliable and valid way of diagnosing problems in very young children.