Table 2 Relapse rates and relative risks of relapse before and after the addition of quetiapine to ongoing therapy

Observation period (in months)

Average

7.5

15.7

Range

3–18

6–42

Relapse rate (episodes/year)

Any episode

2.09

0.61

Manic/mixed episodes

1.15

0.46

Depressive episodes

0.94

0.14

Relative risk of relapse before add-on quetiapine

Any episode

3.4 (χ² = 24.8, 95% CI 2.1–5.5; P < 0.001)

Manic/mixed episodes

2.5 (χ² = 9.0, 95% CI 1.4–4.5; P < 0.05)

Depressive episodes

6.7 (χ² = 24.7, 95% CI 3.7–14.0; P < 0.001)