Table 1.

Characteristics of the included RCTs

Study	Country	Diagnostic criteria	Type of TTH	Interventions	Treatment duration (weeks)	Follow-up duration (weeks)	Number of patients	Female (%)	Mean ages
TCAs
Bendtsen 1996 [42]	Denmark	IHS	Chronic	Amitriptyline 75 mg vs. placebo	8	0	40	63	40
Bettucci 2006 [47]	Italy	IHS	Chronic	Amitriptyline 20 mg vs. amitriptyline 20 mg plus tizanidine 4 mg	12	0	18	72	35.3
Boline 1995 [52]	USA	IHS	Episodic	Amitriptyline 30 mg vs. spinal manipulation	6	4	150	61	42
Boz 2003 [6]	Turkey	IHS	Chronic	Amitriptyline 25 mg vs. sertraline 50 mg	12	0	90	88	39.1
Damapong 2015 [43]	Thailand	IHS	Chronic	Amitriptyline 25 mg vs. massage	4	2	60	87	49.8
Deodato 2019 [51]	Italy	IHS	Chronic	Amitriptyline 50 mg vs. osteopathic manipulative therapy	12	0	24	60	47
Holroyd 1991 [41]	USA	IHS	Chronic	Amitriptyline 75 mg vs. cognitive-behavioral therapy	12	0	41	80	32.3
Holroyd 2001 [5]	USA	IHS	Chronic	Amitriptyline 100 mg vs. placebo	8	24	203	76	37
Indaco 1988 [45]	Italy	Ad Hoc criteria	Chronic	Amitriptyline 50 mg vs. placebo	12	0	36	52	61.2
Langemark 1990 [24]	Denmark	IHS	Chronic	Clomipramine 150 mg vs. mianserin 60 mg vs. placebo	6	0	114	NA	41
Mitsikostas 1997 [46]	Greece	IHS	Chronic	Amitriptyline 50 mg vs. buspirone 30 mg	12	0	58	62	42.5
Mousavi 2011 [48]	Iran	IHS	Chronic	Imipramine 50 mg vs. TENS	12	0	138	46	28.2
Okasha 1973 [53]	Egypt	Ad Hoc criteria	Psychogenic	Amitriptyline 30 mg vs. doxepin 30 mg vs. diazepam 6 mg vs. placebo	8	0	80	28	NA
Pfaffenrath 1994 [50]	Germany, Austria, Switzerland	IHS	Mixed	Amitriptyline 75 mg vs. placebo	12	8	197	56	38
Surbakti 2017 [49]	Indonesia	IHS	Chronic	Amitriptyline 12.5 mg vs. flunarizine 5 mg vs. flunarizine 10 mg	2	0	95	82	44.6
Vernon 2009 [44]	Canada	IHS	Chronic	Amitriptyline 25 mg plus chiropractic vs. Amitriptyline 25 mg plus sham chiropractic vs. placebo plus sham chiropractic	14	12	20	80	33.9
Acupuncture
Chassot 2015 [36]	Brazil	IHS	Chronic	Acupuncture, twice/week vs. sham acupuncture, twice/week	5	0	34	100	40.3
Ebneshahidi 2005 [40]	Iran	IHS	Chronic	Acupuncture, 3 times/week vs. sham acupuncture, 3 times/week	4	12	50	80	35.8
Endres 2007 [29]	Germany	IHS	Mixed	Acupuncture, twice/week vs. sham acupuncture, twice/week	6	24	409	78	39.1
Gildir 2019 [26]	Turkey	IHS	Chronic	Acupuncture, 3 times/week vs. sham acupuncture, 3 times/week	2	4	160	43	36.4
Guo 2020 [32]	China	IHS	Mixed	Acupuncture, once every other day vs. eperisone hydrochloride 150 mg plus flunarizine hydrochloride	4	0	150	62	33.7
Jena 2008 [30]	Germany	IHS	Mixed	Acupuncture, 15 times/12w vs. usual care	12	12	1265	NA	NA
Karst 2001 [38]	Germany	IHS	Mixed	Acupuncture, twice/week vs. sham acupuncture, twice/week	5	20	69	55	48.1
Kawk 2007 [39]	Korea	IHS	Chronic	Acupuncture, twice/week vs. sham acupuncture, twice/week	4	12	32	NA	81
Melchart 2005 [11]	Germany	IHS	Mixed	Acupuncture, 1–2 times/week vs. sham acupuncture, 1–2 times/week vs. waiting list	8	16	270	74	42.7
Schiller 2021 [33]	Germany	IHS	Mixed	Acupuncture, twice/week vs. usual care vs. medical training therapy	6	18	72	74	38.5
Silva 2012 [28]	Brazil	IHS	Mixed	Acupuncture, 8–12 times/8week vs. usual care	8	0	43	100	27.3
Söderberg 2006 [31]	Sweden	IHS	Chronic	Acupuncture, once/week vs. physical training vs. relaxation training	10–12	24	90	81	37.4
Wang 2007 [34]	Denmark	IHS	Chronic	Acupuncture, 14 times/week vs. sham acupuncture, 14 times/week	4	6	40	50	45.3
White 1996 [25]	UK	IHS	Episodic	Acupuncture, once/week vs. sham acupuncture, once/week	6	3	10	70	57.3
White 2000 [27]	UK	IHS	Episodic	Acupuncture, once/week vs. sham acupuncture, once/week	5	12	50	76	49
Xu 2015 [35]	China	IHS	Mixed	Acupuncture, 3 times/week vs. head acupuncture, 3 times/week	4	0	60	67	NA
Xue 2004 [37]	Australia	IHS	Mixed	Acupuncture, twice/week vs. sham acupuncture, twice/week	4	0	40	65	42.1
Zheng 2022 [10]	China	IHS	Chronic	Acupuncture, 2–3 times/week vs. sham acupuncture, 2–3 times/week	8	24	218	79	43.1

RCT, randomized controlled trial; TTH, tension-type headache; TCAs, tricyclic antidepressants; IHS, International Headache Society