Table 5.

The main features of PDA outlined by Newson and colleagues [1] and the 11 DISCO PDA items deemed most useful in identifying PDA, organised to correspond with Newson’s criteria

Newson’s description	Relevant DISCO item description	DISCO item code
Continues to resist ordinary demands with strategies of avoidance that are essentially ‘socially manipulative’	Lack of co-operation	LACKCOP
	Apparently manipulative behaviour	MANBEH*
Surface sociability, but lack of sense of identity, pride or shame	Awareness of own identity	CIDENT*
	Socially shocking behaviour	SHOCK*
	Behaviour in public places	BEHAPUB
	Fantasising, lying, cheating, stealing	LYING*
Lability of mood, impulsive, led by need to control	Inappropriate sociability (rapid, inexplicable changes from loving to aggression)	CINAPP*
	Using age peers as mechanical aids, bossy and domineering	CPEERAD*
	Difficulties with other people	DIFPEOP
Comfortable in role play and pretending	Repetitive acting out roles	CTROL*
Obsessive behaviour (often social in nature)	Harassment of others	HARAS*
Neurological involvement	None included
Passive early history	None included
Language delay	None included

Items that were included in Wing and Gould’s draft 15-item PDA list are designated with an asterisk. Full DISCO item descriptions are given in Online Resource 2