Table 3.

The proportion of variance explained in the latent depression phenotype by the additive genetic factor (heritability; h²), the unique environment (e²), and the common environment (c²) at each occasion (year of data collection)

Occasion	MZ		DZ		h2	e2	c2
	Twin 1	Twin 2	Twin 1	Twin 2
1991	290	297	456	450	0.52 (0.37; 0.61)	0.46 (0.38; 0.57)	0.03 (0.01; 0.15)
1995	300	306	426	432	0.62 (0.51; 0.70)	0.37 (0.29; 0.45)	0.02 (0.01; 0.14)
1997	342	335	334	343	0.63 (0.48; 0.71)	0.35 (0.28; 0.45)	0.04 (0.01; 0.21)
2000	472	457	409	420	0.52 (0.35; 0.61)	0.45 (0.38; 0.54)	0.04 (0.01; 0.20)
2002	221	227	178	170	0.51 (0.40; 0.59)	0.48 (0.40; 0.55)	0.03 (0.01; 0.15)
2009	891	896	874	835	0.51 (0.41; 0.58)	0.47 (0.42; 0.53)	0.02 (0.00; 0.11)
2011	144	149	171	172	0.52 (0.37; 0.60)	0.46 (0.40; 0.54)	0.04 (0.01; 0.21)
2013	486	479	517	543	0.50 (0.40; 0.57)	0.49 (0.43; 0.56)	0.02 (0.01; 0.10)

The 99 % Highest Posterior Density regions are in brackets for h², e², and c²