Chain reaction or time bomb: a neuropsychiatric-developmental/neurodevelopmental formulation of tourettisms, pervasive developmental disorder, and schizophreniform symptomatology associated with PANDAS.

We present the case of a boy who over time sequentially exhibited symptoms consistent with a pervasive developmental disorder, schizophreniform symptomatology, multiple motor and vocal tics, and myoclonus. During this period he experienced multiple episodes of group A beta-haemolytic streptococcal (strep) infection confirmed by culture and serological studies. We speculate that paediatric autoimmune neuropsychiatric disorder associated with strep (PANDAS) may have served as an element in a complex chain of causation influencing the expression of his symptoms. Our main emphasis is to utilize our case study as an example of the application in case formulation of the neuropsychiatric developmental model and of the neurodevelopmental model on symptom ontogenesis and clinical outcome.