Table 1.
Descriptive information on studies included in the meta-analysis.
| Study | Year | Sex | Mean Age | Location | Measure (construct) | All N | Male N | Female N |
|---|---|---|---|---|---|---|---|---|
| Benjamin | 2000aR | MF▲ | 26.95 | Israelu | TPQ (HA) | 454 | -- | -- |
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| Henderson | 2000 | MF | 42.05 | Australiac | BIS (BI) | 870 | 407 | 463 |
| DSSI (Anx) | 870 | 407 | 463 | |||||
| EPQ-R-S (N) | 868 | 405 | 463 | |||||
| Goldberg (Anx) | 870 | 407 | 463 | |||||
| PANAS (NA) | 965 | 502 | 463 | |||||
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| Eley | 2003E,X | F | 36.59 | Germanyc | NEO-FFI (N) | 71 | -- | 71 |
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| Kim (A) | 2004H | MF | 25.77 | USc | TCI (HA) | 349 | 164 | 185 |
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| Kim (B) | 2004 | F | 24.73 | USa | TCI (HA) | 64 | -- | 64 |
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| Tsai | 2004 | F | 20.00 | Taiwana | TPQ (HA) | 120 | -- | 120 |
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| Harris | 2005 | MF | 79.06 | Scotlandc | HADS (Anx) | 533 | 223 | 310 |
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| Olsson | 2005X | MF | 24.09 | Australiac | CIS-R (Anx) | 803 | 338 | 465 |
| 2007 | NEO (N) | 801 | 338 | 463 | ||||
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| Reuter | 2005 | MF | 24.39 | Germanyc | NEO-FFI (N) | 363 | 101 | 262 |
| TCI (HA) | 363 | 101 | 262 | |||||
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| Hoth | 2006 | MF | 39.68 | (mixed)c | DASS (Anx) | 402 | 221 | 181 |
| NEO-FFI (N) | 374 | 204 | 170 | |||||
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| Ivanova | 2006 | MF | 36.82 | Bulgaria c | TCI (HA) | 102 | 40 | 62 |
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| Kim | 2006 | MF | 23.00 | Koreaa | TCI (HA) | 286 | 138 | 148 |
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| Reuter | 2006 | MF | 25.57 | Germanyc | BIS (BI) | 295 | 143 | 152 |
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| Tochigi | 2006 | MF▲ | 37.40 | Japana | NEO-PI-R (N) | 248 | -- | -- |
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| Golimbet | 2007 | MF | 31.55 | Russiac | EPI (N) | 270 | 98 | 172 |
| MMPI (Pt) | 269 | 99 | 170 | |||||
| TCI (HA) | 211 | 68 | 143 | |||||
|
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| Hashimoto | 2007H | MF | 36.32 | Japana | TCI (HA) | 139 | 47 | 92 |
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| Ishii | 2007 | MF | 29.30 | Japana | TCI (HA) | 478 | 246 | 232 |
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| Urata | 2007X | F | 20.00 | Japana | NEO-FFI (N) | 235 | -- | 235 |
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| Bækken | 2008X | MF | 50.61 | Norwayc | HADS (Anx) | 5,651 | 2,629 | 3022 |
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| Hettema (A) | 2008E,X | MF | 37.41 | USc | EPQ-R-S (N) | 359 | 186 | 173 |
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| Hettema (B) | 2008E,X | MF | 36.47 | USc | EPQ-R-S (N) | 712 | 471 | 241 |
|
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| Montag | 2008C | F | 22.11 | Germanyc | BIS (BI) | 96 | -- | 96 |
|
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| Wray | 2008E,X | MF | 40.14 | Australiac | EPQ-R-S (N) | 954 | 403 | 551 |
|
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| Arias | 2010 | MF | 21.87 | Spainc | STAI-T (Anx) | 456 | 200 | 256 |
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| Hatzimanolis | 2010 | F | 39.60 | Greecec | EPQ (N) | 381 | -- | 381 |
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| Middeldorp | 2010 | MF | 56.46 | Netherlandsc | YASR (Anx) | 274 | 124 | 150 |
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| Calati | 2011 | MF | 45.22 | Germanyc | TCI (HA) | 289 | 123 | 166 |
|
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| Chen | 2011 | MF | 20.47 | Chinaa | BAI (Anx) | 556 | 250 | 306 |
| BIS (BI) | 556 | 250 | 306 | |||||
| TCI (HA) | 556 | 250 | 306 | |||||
|
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| Desmeules | 2011 | F | 50.00 | Switzerlandc | STAI-T (Anx) | 74 | -- | 74 |
|
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| TOTAL (27 studies / 29 independent samples) | 15,979 | 6,648 | 8,630 | |||||
Abbreviations (measures): BAI = Beck Anxiety Inventory (Beck and Steer, 1990); BIS = Behavioral Inhibition System Scale (Carver and White, 1994); CIS-R = Clinical Interview Schedule – Revised (Lewis et al., 1988); DASS = Depression Anxiety Stress Scales (Anxiety subscale; Lovibond and Lovibond, 1995); DSSI = Delusions-Symptoms-States Inventory (Anxiety scale; Bedford et al., 1976); EPI = Eysenck Personality Inventory (Eysenck and Eysenck, 1964); EPQ = Eysenck Personality Questionnaire (Eysenck and Eysenck, 1975); EPQ-R-S = EPQ-Revised-short form (Eysenck and Eysenck, 1991); Goldberg = Goldberg anxiety scale (Goldberg et al., 1988); HADS = Hospital Anxiety and Depression Scale (anxiety subscale; Zigmond and Snaith, 1983); MMPI-Pt = Minnesota Multiphasic Personality Inventory (Psychasthenia subscale) (Hathaway and McKinley, 1940); NEO = Neuroticism, Extraversion, and Openness Personality Inventory (Costa & McCrae, 1985); NEO-FFI = NEO Five Factor Inventory (Costa & McCrae, 1992); NEO-PI-R = NEO Revised (Costa et al., 1991); PANAS = Positive and Negative Affect Schedule (short form; Mackinnon et al., 1999); STAI-T = State Trait Anxiety Inventory (trait form; Spielberger, 1983); TCI = Temperament and Character Inventory (Cloninger et al., 1994); TPQ = Tridimensional Personality Questionnaire (Cloninger et al., 1991); YASR = Young Adult Self-Report (anxious depression scale; Achenbach, 1990).
Abbreviations (constructs): HA = harm avoidance; N = neuroticism; BI = behavioral avoidance; Anx = anxiety; Dep = depression.
Abbreviations (others):a = Asian, c = Caucasian, u = unknown ethnicity. H = HWE flag indicates deviation of genotype frequency from HWE, X = effect sizes provided in odds ratio format and transformed with the Cox method; E = extreme-scoring samples; R = related participants. M = male, F = female, MF = both sexes included; ▲ = studies that did not provide separate statistics for males and females.
- When a sample included multiple measures, N for measure with biggest sample size was used to calculate the total N reported here. Sex-specific N only includes studies that provided sex-specific data. For clarity, each independent sample is placed within the same shaded/unshaded row.
- Olsson et al. (2005) and Olsson et al. (2007) were treated as one study because of the nearly identical samples; they were based on the same study sample (Victorian Adolescent Health Cohort Study. Effect sizes on CIS-R, but not NEO-FFI, were provided in odds ratio format and transformed with the Cox method. On the CIS-R, individuals who reported heightened generalized anxiety symptoms for =>3 waves were coded as “high anxiety” to approximate a median split of the sample.In the 2005 sample, “cases” vs. controls were coded as individuals with 3+ vs. 0–3 waves of generalized anxiety.
- Kim (A) and Kim (B) represent the Caucasian and Asian samples in Kim et al. (2004), respectively. In this study, Hardy-Weinberg equilibrium (HWE) was violated in the Caucasian sample. We excluded the entire sample (Caucasian and Asian) from HWE sensitivity analyses. This study included Asian males, but this subgroup was excluded from our meta-analysis due to N=0 with the rs4680 met/met genotype.
- Hettema (A) and Hettema (B) represent the two-stage independent samples in Hettema et al. (2008).
- In Hashimoto et al. (2007), deviation from HWE was observed only in the combined sex sample, but to be conservative, we removed the study from all HWE sensitivity analyses.