TABLE S2.

Response Rates in the Avon Longitudinal Study of Parents and Children (ALSPAC) Age 13 Mother-Completed Questionnaires to Each of the Detailed Questions about Specific Tics and Their Frequencies

Response	C1: Repeated Movements of Face and Head	C2: Repeated Movements of Neck, Shoulder, or Trunk	C4: Repeated Noises and Sounds in Past Year	Response	C6b: Frequency of These Habits
Definitely	327 (4.8%)	125 (1.9%)	308 (4.6%)	< Once a month	150 (2.2%)
Probably	303 (4.5%)	203 (3.0%)	479 (6.6%)	1–3 Times a month	164 (2.4%)
Not at all	6,063 (89.6%)	6,336 (93.6%)	5,910 (87.3%)	About once a week	151 (2.2%)
Missing	75 (1.1%)	104 (1.5%)	106 (1.6%)	> Once a week	501 (7.4%)
				Every day	667 (9.9%)
				Missing/NA	5,135 (75.9%)

Note: Exclusions for ID, autism, IQ <80 were conducted before these variables were tabulated.