Table 2.

Characteristics of association studies eligible for inclusion

Study	Year	Inventorya	N	% Male	Mean Age	Ethnicity	HW equilibrium	HW χ2	HW p	Exclusion
Lesch	1996	NEO	505	92	37.6	94% Caucasian	YES	0.01	0.93
Ebstein	1997	TCI	121	55	29.7	74% Caucasian	YES	1.14	0.29
Nakamura	1997	Both	186	0	19.6	Asian	YES	1.15	0.28
Mazzanti	1998	TCI	215	85	35.5	Caucasian	YES	0.01	0.98
Ricketts	1998	TCI	37	nd	nd	Caucasian	YES	2.10	0.15
Flory	1999	NEO	225	50	45.7	84% Caucasian	YES	0.16	0.69
Hamer	1999	TCI	634	43	31.3	79% Caucasian	NO	3.85	0.04	Excludedb
Katsuragi	1999	TCI	101	61	25.0	Asian	YES	0.02	0.88
Kumakiri	1999	Both	144	42	24.4	Asian	YES	1.28	0.26
Benjamin	2000	TCI	455	40	nd	Caucasian	N/A			Excludedd
Comings	2000	TCI	81	100	32.9	Caucasian	YES	0.10	0.75
Du	2000	NEO	186	41	36.3	Caucasian	YES	0.77	0.38
Greenberg	2000	NEO	397	16	28.6	Caucasian	NO	4.75	0.03	Excludedb
Herbst	2000	TCI	425	51	43.8	67% Caucasian	YES	0.79	0.38
Hu	2000	NEO	759	62	29.2	81% Caucasian	YES	1.57	0.21
Osher	2000	Both	148	34	30.7	Caucasian	YES	0.11	0.75
Schmidt	2000	NEO	72	48	27.0	54% Caucasian	YES	0.06	0.80	Excludedc
Samochowiec	2001	TCI	126	30	23.8	Caucasian	YES	1.26	0.26
Cohen	2002	TCI	559	0	nd	Caucasian	NO	9.51	0.01	Excludedb
Tsai	2002	TCI	192	49	29.3	Asian	YES	2.30	0.13
Brummett	2003	NEO	99	32	70.3	87% Caucasian	YES	0.70	0.40
Umekage	2003	NEO	244	8	37.7	Asian	YES	2.08	0.15
Ham	2004	TCI	146	32	31.9	Asian	YES	0.01	0.98
Jacob	2004	Both	281	25	22.4	Caucasian	YES	0.59	0.44
Lang	2004	NEO	228	50	38.6	Caucasian	YES	1.14	0.29
Park	2004	TCI	100	0	48.3	Asian	YES	2.41	0.12	Excludedd
Samochowiec	2004	Both	100	47	41.0	Caucasian	YES	0.04	0.85
Szekely	2004	TCI	151	43	22.2	Caucasian	YES	0.59	0.44
Thierry	2004	TCI	76	0	32.8	Caucasian	YES	0.01	0.96	Excludedd
Sen	2004	NEO	415	33	43.8	Caucasian	NO	3.76	0.05	Excludedb
Bachner-Melman	2005	TCI	872	nd	21.4	N/A	N/A			Excludedc,d
Hariri	2005	TCI	92	49	30.5	Caucasian	N/A			Excludedd
Kim	2005	TCI	211	51	26.5	Asian	YES	0.06	0.81	Excludedd
Kremer	2005	TCI	730	nd	nd	N/A	N/A			Excludedc,d
Dragan	2006	NEO	196	0	21.7	Caucasian	YES	2.07	0.15
Lazagorta	2006	TCI	57	nd	45	Other	YES	3.70	0.05	Excludedb,c
Monteleone	2006	TCI	94	0	nd	Caucasian	YES	2.37	0.12
Serretti	2006	TCI	132	nd	nd	Caucasian	YES	0.02	0.90
Vorfelde	2006	Both	195	50	nd	Caucasian	YES	0.48	0.49
Hunnerkopf	2007	NEO	272	25	21.9	Caucasian	N/A			Excludedd
Joo	2007	TCI	158	44	23.8	Asian	YES	0.13	0.72
Nilsson	2007	TCI	196	60	17	Caucasian	YES	1.07	0.30
Schmitz	2007	Both	410	36	24	Caucasian	YES	0.07	0.78
Stein	2008	NEO	247	31	18.8	61% Caucasian	NO	3.88	0.05	Excludedb
Lee	2008	TCI	75	100	16.1	Asian	YES	2.97	0.08	Excludedd
Kazantseva	2008	TCI	301	20	19.8	Caucasian	YES	1.24	0.26
Suzuki	2008	TCI	575	51	28.7	Asian	YES	0.14	0.71
Munafò	2009	TCI	3872	44	42	Caucasian	YES	0.26	0.61
Gonda	2009	TCI	169	0	nd	Caucasian	YES	0.20	0.65
Terraccianoe	2009	NEO	3972	43	42.5	Caucasian	YES	1.33	0.25
Terraccianof	2009	NEO	1182	52	57.3	71% Caucasian	YES	0.87	0.35
Saiz	2010	TCI	404	50	40.5	Caucasian	YES	0.76	0.38
Present Study		TCI	229	45	49.2	Caucasian	YES	0.33	0.56

HW = Hardy-Weinberg; HW χ2 = Hardy-Weinberg chi square; HW p = Hardy-Weinberg p value; nd = not determined; N/A = not applicable.

^a The term NEO referred to all versions (i.e. NEO-PI, NEO-PI-R, NEO-FFI); the term TCI referred to all versions (TPQ).

^b Excluded because genotype frequencies showed deviation from Hardy-Weinberg equilibrium.

^c Excluded due to the ethnic heterogeneity or lack of data about ethnic origin.

^d Excluded because of unavailable data.

^e Data referred to SardiNIA sample.

^f Data referred to BLSA (Baltimore Longitudinal Study of Aging) sample.