Table 2.
Cumulative lifetime prevalence of common adult mental disorders from age 18 to 32 years. Adult disorders accumulated across four prospective assessments at ages 18, 21, 26 and 32 in the Dunedin Study are compared against lifetime prevalence up to age 32 based on retrospective recall in the New Zealand Mental Health Survey (NZMHS) and the two US National Comorbidity Surveys (NCS and NCS-R)
| Disorder | Dunedin Study (n=1000) | NZMHS (n=3173) | NCS-R (n=2676) | NCS (n=3340) |
|---|---|---|---|---|
| Any anxiety | ||||
| % | 49.5 | 28.3 | 33.1 | 25.4 |
| (no. of cases) | (495) | (920) | (853) | (840) |
| [CI] | [46.4–52.6] | [25.8–30.9] | [30.8–35.5] | [23.1–27.8] |
| Panic | ||||
| % | 6.5 | 3.2 | 4.7 | 3.0 |
| (no. of cases) | (65) | (121) | (130) | (103) |
| [CI] | [5.0–8.0] | [2.5–3.9] | [3.9–5.6] | [2.3–4.0] |
| Specific phobia | ||||
| % | 18.8 | 12.7 | 13.3 | 10.8 |
| (no. of cases) | (188) | (440) | (385) | (349) |
| [CI] | [16.4–21.2] | [11.2–14.2] | [11.8–14.9] | [9.2–12.6] |
| Social phobia | ||||
| % | 27.9 | 10.8 | 13.6 | 14.3 |
| (no. of cases) | (279) | (388) | (369) | (469) |
| [CI] | [25.1–30.7] | [9.5–12.1] | [12.2–15.0] | [12.6–16.2] |
| GAD | ||||
| % | 14.2 | 6.1 | 5.6 | 4.7 |
| (no. of cases) | (142) | (223) | (159) | (142) |
| [CI] | [12.0–16.4] | [5.0–7.1] | [4.5–6.7] | [3.8–5.9] |
| Depression | ||||
| % | 41.4 | 18.5 | 19.0 | 16.9 |
| (no. of cases) | (414) | (621) | (526) | (582) |
| [CI] | [38.3–44.5] | [16.7–20.2] | [17.5–20.6] | [14.9–19.0] |
| Alcohol dependence | ||||
| % | 31.8 | 6.3 | 6.4 | 16.9 |
| (no. of cases) | (318) | (262) | (151) | (590) |
| [CI] | [28.9–34.7] | [5.2–7.4] | [5.2–7.9] | [15.1–18.9] |
| Cannabis dependence | ||||
| % | 18.0 | 9.8 | 3.9 | 9.7 |
| (no. of cases) | (180) | (354) | (96) | (334) |
| [CI] | [15.6–20.4] | [8.4–11.1] | [3.2–4.9] | [8.5–11.0] |
GAD, Generalized anxiety disorder ; CI, confidence interval.
n’s for NCS-1, NCS-R and NZMHS are unweighted. The Dunedin Study denominator is n assessed at one or more of four study phases=1000.
Certain anxiety disorders were only assessed in Part II of the NZMHS (the long form), thus the total n for any anxiety is reduced to 2057. Certain anxiety disorders, alcohol dependence and cannabis dependence were only assessed in Part II of the NCS-R (the long form), thus the total n for these variables is reduced to 1728.
Lifetime prevalence in Dunedin was the sum of past-year cases from assessments at ages 18, 21, 26 and 32. This period thus covered 15 years. Lifetime prevalence in the NZMHS, NCS-R and NCS was based on retrospective recall by respondents aged 18–32 years. The 18–32 years group were able to recall disorder back to childhood. Presuming that the survey respondents could recall back to age 10; then 18-year-olds could recall an 8-year period, 19-year-olds could recall a 9-year period, and so forth, until 31-year-olds could recall a 21-year period and 32-year-olds could recall a 22-year period. Therefore, the average recall period for the three surveys was 15 years, which is the same as the Dunedin Study period.