Extreme ("pathological") demand avoidance in autism: a general population study in the Faroe Islands.

Research into Pathological Demand Avoidance (PDA), which has been suggested to be a subgroup within the Autism Spectrum Disorder (ASD), is almost nonexistent in spite of the frequent reference to the condition in clinical practice. The total population of 15 to 24-year-olds in the Faroe Islands was screened for ASD, and 67 individuals were identified who met diagnostic criteria for ASD (corresponding to a general population prevalence of ASD of almost 1 %). Of these 67, 50 had parents who were interviewed using the Diagnostic Interview for Social and Communication Disorders (DISCO-11) which contains 15 "PDA-specific" items. Nine individuals met criteria for "possible clinical diagnosis of PDA", meaning that almost one in five of all with ASD also had indications of having had PDA in childhood, and that 0.18 % of the total population had had the combination of ASD and PDA. However, at the time of assessment, only one of the 9 individuals with possible PDA still met "full criteria". PDA possibly constitutes a considerable minority of all cases with ASD diagnosed in childhood, but criteria for the condition are unlikely to be still met in later adolescence and early adult life.