Table.

Follow-up studies of tic disorders.

Ref.	Year	N (orig.)	N (f/up)	Sample	Age (orig.) (years)	Age (f/up) (years)	Follow-up duration (y)	Assessment	Recovery	Comments
[61]	1930	49	31	Tics, C&A	n/a	n/a	(2-3)	Clinical Interview	65% free of tics.	Age of onset was (“<5”-14)
[62]	1954	53	49*	Tics, C&A	n/a	(7-18)	(1-5)	Clinical interview	24% had been free of tics for at least a year.	* “The information was sufficiently accurate for statistical analysis in only 41 cases, but since they appeared to be fairly representative of the total sample, it is doubtful whether the remaining cases would have influenced the findings to any appreciable degree.” Age of onset was (3.5-12.5)
[36]	1962	237	220	Tics, C&A	9 (2-16)	18 (6-26)	9 (1-15)	Parent interview, “most” children seen	By 6 months after first encounter: 37 remissions, 9 of which later recurred. At follow-up, tics had improved in 94%, only 20-40% had daily tics, and 50% had been tic-free for 1 year or more.	Mean age of tic cessation was “12-13 years.” 90% of children with a parent who had tics in adulthood still had tics, vs. <45% of children whose parent had tics only in childhood.
[63, 64]	1976	80	78	TS, C&A	(2-16)	(6-67)	2.7 (0.6-8.6)	Clinical interview	4 patients reported a complete remission, and 6 patients experienced remission (from months to three years) followed by returning symptoms.	Those on haloperidol had a mean improvement of 79%; those on other or no medication 25%.
[65]	1987	99	58	Teens and young adults; DSM-III criteria	8 (median) ± 3.2 (2-15)	18 (median) ± 2.6 (15-25)	n/a	Self-report questionnaire	26% tics essentially gone 47% considerable improvement 14% stable 14% worsened tics	53 of 55 patients who had been treated with medications received haloperidol, and 45% of the 53 experienced major improvement.
[4]	1988	†	50	TS; DSM-III criteria	18.9 ± 12.0 (4-69) ‡		13-20	Clinical exam with a large set of specified data points	3 of the 50 had remitted for >7 years. Of the whole sample, 27% had experienced a spontaneous complete remission of tics for at least a week (but in 2/3 of these it lasted <6 months).	†These are “the first 50 consecutive patients who were carefully followed up to the present time” from a total sample of 666 patients with DSM–III TS. See pp. 169-175 in ref. [4]. ‡Age and follow-up duration describe the total sample n=666; the stats for the subsample n=50 are not given.
[25]	1990	131	63	Tics, C&A	Modal age of onset is 7	(15-29)	n/a ¶	Clinical interview	38% recovered completely, 62% had occasional relapses lasting a few days, and 14% still had tics requiring treatment.	¶ 131 patients were hospitalized 1968-1988
[66]	1990	75	33	TS, C&A, adults	19 ± 14 (9-50)	25 ± 19 (13-59)	7 ± 4(1-15)	Clinical interview	All patients reported some sort of improvement, which was found in 70% of those treated with pimozide and 78% of those treated with haloperidol.
[21]	1992	93	58	Adults	n/a	21.2 ± 8.6 (21-62)	n/a	Clinical interview, direct observation	All adults still had tics.	Video of patient alone in the room. Age of tic onset 6.9 ± 2.8.
[67]	1994	126	23	TS, C&A, adults	17.7 ± 8 (7-61)	22.1 ± 11.3 (11-53)	About 5 (1989 to 1994)	Clinical interview	13% of subjects showed improvement in sum of tics subtypes and severity.
[11]	1997	58	58	C&A, DSM-III transient tic disorder	n/a	n/a	2-14	Structured phone interview (62%), on-site interview (38%)	17% tics absent throughout follow-up period; 40% now chronic motor or vocal tic disorder; 43% chronic or episodic tics (either TS or tic disorder not otherwise specified).
[52]	1998	42	38	TS, C&A	n/a ⁑	Phone followup: 11.0 ± 2.9 (5.9-16.9), in-person followup: 18.4 ± 1.0 (17-20)	7.3	Clinical interview	“By 18 years of age nearly half of the cohort was virtually tic-free.”	Data available on 36 ⁑ All subjects born in 1975
[68]	2001	54	39	TS, school-aged children	10.1 (3-17.9)	22.8 (14-28)	13	Structured phone interview, self-report questionnaire	44% “essentially symptom free”; 22% on medication.
[45]	2001	976	Time 2 = 776, Time 3 = 760, Time 4 = 728	Tics, C&A	6.1 ± 2.8 (1-10)	Time 2: 13.7 ± 2.7 (9-20) Time 3: 16 ± 2.8 (11-22) Time 4: 22.1 ± 2.7 (17-28)	Time 2: 8, Time 3: 10, Time 4: 17	Clinical interview	Tics (and ADHD) decreased in prevalence throughout time.	At time 2, 54 families were lost so a representative supplemental sample was selected to replace them.
[8]	2001	45	45	Adults	ADHD with tics: 37.0 ± 11.8 No ADHD, some with tics: 39.7 ± 8.3	n/a	n/a	Clinical interview (retrospective data)	By age 20, “the age-adjusted rate of complete remission of the tic disorder was 62.2%; the unadjusted rate was 53% (N=19 of 36).”	This study used retrospective data and DSM-III-R. Their figure 1 shows a survival curve for tic remission in this sample.
[69]	2003	31	31	TS, Adults	22.8 ± 8.7 (4-33)	31.4 ± 7.6	7.6 ± 8.1 (0-26)	Chart review, clinical interview (retrospective data)	24 still had tics and 7 were in remission.	Excludes 2 additional patients in complete remission by chart review who did not return for follow-up.
[20]	2003	56	31	TS, C&A	12.2 ± 2.2 (8-14)	16.2 ± 3.5 (20-n/a)	12	Direct observation, clinical interview	90% of adults still had tics.
[22]	2004	50	50	TS, C&A	10.9 ± 3.4 (6-17)	n/a	2.2 ± 1.7 (0.4-5.5)	Clinical interview	82% of subjects met criteria for tic persistence (compared to 88% at baseline), but impairment was reduced substantially.
[50]	2005	61	43	TS, C&A	11.4 ± 1.6 (8.5-13.9)	18.7 ± 1.7 (16-23)	7.5 ±1.9 (3.8-12.8)	Clinical interview (in-person or via phone)	Few tic symptoms at follow-up, on average. 19% had tics of moderate or greater severity (YGTSS score > 20) compared to 51% initially.	Tic severity at follow-up correlated inversely with baseline caudate nucleus and right putamen volumes.
[39]	2006	64	46	TS, C&A	11.4 ± 1.6 (7.5-13.0)	19.0 ± 1.8 (16.0-22.8)	7.6 ± 1.9 (3.8-12.8)	Clinical interview	Tics had improved by adolescence in 85%. One third had a YGTSS score of 0, indicating no evidence of tics over the past week.
[70]	2009	180	58	TS, adults	n/a	29 ± 9.8 (19-55)	n/a	Self-report questionnaire	53% improvement, 22% worsening of tics, 24% no change.
[71]	2015	482	83	TS, C&A	9.8 ± 3.1	25.6 ± 7.4(18-61)	n/a	Self-report questionnaire	13.6% reported no motor tics, and 59.3% reported no vocal tics.	Initial visits were between 1972-2007
[15]	2017	314	227	C&A	12.4 ± 2.8 (5-19)	18.5 ± 2.8 (11.1-25.9)	6 (4-8)	Clinical interview	After age 16, 82% still had tics; 23% had moderate or severe tics.
[13]	2019	43 ǁ	39	PTD, C&A	8.13 ± 2.43, (5.0-10.9)	n/a	0.75 ± 0.11, (0.51-0.96)	Clinical assessment, questionnaires, video of the child alone	Every child (N=39) still had tics at the follow-up visit, though in some cases they were not aware of them, or tics manifested only when the child was alone, observed by video.	Follow-up was at the 1-year anniversary of the first tic. ǁ This line and the following line come from overlapping samples in the same study.
[42]	2019	55	45	PTD, C&A	7.74 ± 2.02 (5.03-12.9)	n/a	0.73 ± 0.13, (0.31-0.96)	Clinical assessment, questionnaires, video of the child alone		Children who were initially able to better suppress their tics in the presence of a reward showed better tic outcome at follow-up.
[72, 73]	2020	126	80	TS; C&A	11.61 ± 2.41	n/a	Around 10 years	Clinical interview	Tics improved in both groups; acute responders to PST returned to baseline tic severity at follow-up, while CBIT responders stayed better; YGTSS impairment score was reduced in acute responders regardless of treatment and maintained at follow-up, while nonresponders eventually had similar scores as responders.	Follow-up of the large child CBIT study (preliminary reports)

Age appears as M ± SD (range) except where indicated. Ref.: reference number in bibliography. (orig.): initial sample. (f/up): at follow-up. n/a: not available. TS: Tourette syndrome. C&A: child and adolescent. PTD: Provisional tic disorder (DSM-5). CBIT: Comprehensive Behavioral Interventions for Tics. PST: Supportive psychotherapy and education.