Table 2

Results of factor analysis showing the questions which load on each factor and their eigenvalues

	Factor I	Factor II	Factor III	Factor IV
Clockwatching	0.78	0.06	0.17	0.06
Ritualistic behaviour	0.75	0.14	0.15	−0.01
Use of a catchphrase	0.65	0	0.21	0.2
Sweet food	0.61	0.08	−0.03	−0.03
Appetite increase	0.6	0.21	0.21	−0.01
Counting/numbers	0.51	0.19	0.01	0.24
Mental rigidity	0.49	0.14	0.53	0.19
Self-care	0.25	0.64	−0.04	0.32
Poor judgement	0.2	0.64	−0.04	0.32
Lack of planning	0	0.63	0.26	0.13
Aberrant motor behaviour	0.21	0.6	0.24	−0.27
Distractibility	0.28	0.6	0.27	−0.02
Apathy	0.18	0.56	−0.02	0.48
Mood changes	0.18	0.1	0.78	0.22
Irritability	0.11	0.23	0.76	0.15
Aggression	0	0.19	0.67	0.15
Depression	−0.02	0.15	0.58	0.22
Disinhibition	−0.07	−0.05	0.14	0.55
Reduced interest in family	0.37	0.41	0.14	0.53
Conversational disinhibition	0.1	−0.04	0.23	0.53
Social withdrawal	0.35	0.46	−0.16	0.51
Reduction in conversation	0.39	0.44	−0.01	0.5
Lack of empathy	0.51	0.08	0.39	0.49