Table 1.

Study characteristics.

Author (year)	Diagnostic criteria	Insomnia duration	Assessment	Comorbidity	N insomnia	N controls	%Female insomnia	% Female controls	Age insomnia (M)	Age controls (M)	Pharmaco intake	Caffeine intake	Alcol intake	Time of testing
Altena et al., 2008	RDC, Lichstein criteria	>2.5 years	Questionnaire	Subclinical psychiatric symptoms	21	12	80.9	75	61	60	Excluded	n/a	n/a	PM
Backhaus et al., 2006	DMS-IV	9.2 years	Clinical interview	Excluded	15	13	50	61.3	41.6	40.1	Excluded	n/a	n/a	AM
Bonnet and Arand, 1995	SOL>45 or WASO>60 min, 4 nights per week for 1 year	8 years	Questionnaire	Excluded	10	10	n/a	n/a	38.3	38.6	Excluded	Excluded	n/a	Repeated testing
Cellini et al., 2014	RDC	n/a	Clinical interview, questionnaire	Excluded	13	13	61.5	46.1	23.3	24.3	Excluded	Excluded	Excluded	PM
Chen et al., 2016	ICSD-3	>6 months	Questionnaire	Excluded	21	20	71.4	65	41.8	38.1	n/a	n/a	n/a	AM
Covassin et al., 2011	DSM-IV	n/a	Clinical interview, questionnaire	Excluded	8	8	50	50	22.9	24.8	Excluded	Excluded	Excluded	Repeated testing
Crenshaw and Edinger, 1999	DMS-III-R	n/a	Clinical interview	Excluded	32	32	50	50	67.7	67.5	Excluded	n/a	n/a	Repeated testing
Edinger et al., 2000	DMS-III-R	>6 months	Clinical interview	Excluded	27	31	44.4	51.6	49.7	46.4	Excluded	n/a	n/a	Repeated testing
Edinger et al., 2008	DSM-IV	n/a	Clinical interview	Excluded	79	84	54.4	48.8	50	48.6	Excluded	n/a	n/a	Repeated testing
Fang et al., 2008	DSM-IV	n/a	Questionnaire, actigraphy	Excluded	18	21	66.7	66.7	34.1	27.8	n/a	Excluded	Excluded	PM
Fortier-Brochu and Morin, 2014	DSM-IV, ICD-10	17.3 years	Clinical interview, diary	Excluded	25	16	56	50	44.4	42.8	Excluded	Excluded	Excluded	AM
Guo et al., 2017	DSM-IV	n/a	Questionnaire	Excluded	40	48	77.5	72.9	37.3	39.8	Excluded**	n/a	n/a	n/a
Haimov et al., 2008	Lichstein criteria	n/a	Questionnaire, actigraphy	Excluded	35	64	57.1	67.2	73.6	71.6	Excluded	n/a	n/a	PM
Joo et al., 2013	ICSD-2	>1 year	Clinical interview, diary, questionnaire	Excluded	27	27	92.5	85	52.3	51.7	Excluded	Excluded	Excluded	n/a
Khassawneh et al., 2018	DSM-5, ICSD-3	n/a	Clinical interview, questionnaire, psg	Excluded	35	54	71.4	70.4	40.6	31.5	Excluded	n/a	n/a	Repeated testing
Liu et al., 2014	DSM-IV	6.4 years	Clinical interview, questionnaire	Excluded	36	26	58.3	61.5	42.9	40.5	Excluded	Excluded	Excluded	n/a
Lovato et al., 2013	DSM-IV	n/a	Clinical interview, questionnaire	Excluded	49	49	55.2	55.2	69.4	70	Excluded	n/a	n/a	n/a
Noh et al., 2012	ICSD-2	7.6 years	Clinical interview	Excluded	20	20	90	90	50.8	50.4	Excluded	Excluded	Excluded	n/a
Perrier et al., 2015	DSM-IV	n/a	Clinical interview, questionnaire	Excluded	21	16	57.1	62.5	48.7	48.3	Excluded	n/a	n/a	PM
Randazzo et al., 2000	DSM-IV	n/a	n/a	Excluded	35	35	71.4	77.1	43.6	43.5	n/a	n/a	n/a	n/a
Rosa and Bonnet, 2000	SOL>45 or WASO>60 min, 4 nights per week for 1 year	7.9 years	Questionnaire, psg	Excluded	121	56	38	32	35	36	Excluded	Excluded	n/a	Repeated testing
Sagaspe et al., 2007	ICSD-2	>6 months	Clinical interview, psg	n/a	13	13	38.4	38.4	47.4	47.4	Excluded	n/a	n/a	PM
Son et al., 2018	DSM-5	4.9 years	Clinical interview, questionnaire	Excluded	21	26	57.1	57.7	36.6	33.2	Excluded	n/a	n/a	AM
Shekleton et al., 2014	RDC	n/a	Clinical interview, questionnaire	Excluded	76	20	57.8	70	35.7	34.7	Excluded	Excluded	n/a	Repeated testing
Siversten et al., 2013	DSM-IV	n/a	Questionnaire	Excluded	30	91	n/a	n/a	n/a	n/a	n/a	n/a	n/a	n/a
Szelenberger and Niemcewicz, 2001	DSM-IV	8.2 years	Questionnaire, actigraphy, psg	Excluded	14	14	57.1	57.1	41.2	36.2	Excluded	n/a	n/a	AM
Varkevisser et al., 2007	ICSD-2	n/a	Clinical interview, diary	n/a	39	20	58.9	50	40.9	42.6	n/a	n/a	n/a	Repeated testing
Vignola et al., 2000	ICSD, DSM-IV	n/a	Clinical Interview, questionnaire, diary	Excluded	20	20	10	10	61.7	63.3	Excluded benzodiazepine	n/a	n/a	AM

AM, morning; DSM, diagnostic and statistical manual of mental disorders; ICD, international classification of diseases; ICSD, international classification of sleep disorders; n/a, not available; PM, afternoon/evening; PSG, polysomnography; RDC, research diagnostic criteria; SEI, sleep efficiency index; SOL, sleep onset latency; TST, total sleep time, WASO, wake after sleep onset. X = no group differences,

^**excluded if could impact cognitive function or reaction times.