Table 2.

Proportion of BPD and ADHD in individuals with the other diagnosis, and in individuals whose relatives have the other diagnosis

	No. of individuals	Proportion of BPD—outcome Percent (95% CI)		Proportion of ADHD—outcome Percent (95% CI)
		No ADHD	ADHD	No BPD	BPD
Within individual
Both sexesa	2,113,902	0.3% (0.3–0.3)	3.6% (3.4–3.7)	3.8% (3.8–3.8)	30.9% (30.0–31.9)
Females onlya	1,031,987	0.6% (0.6–0.6)	8.0% (7.7–8.3)	2.7% (2.7–2.8)	29.6% (28.6–30.5)
Males onlya	1,081,915	0.1% (0.1–0.1)	1.0% (0.9–1.0)	4.8% (4.7–4.8)	40.1% (37.4–42.8)
Full siblings	No. of pairsb
Both sexes	2,211,396	0.4% (0.4–0.4)	0.9% (0.9–1.0)	3.4% (3.4–3.4)	7.8% (7.2–8.4)
Female outcome female exposure	523,464	0.7% (0.7–0.7)	1.9% (1.6–2.1)	2.6% (2.5–2.6)	6.6% (5.8–7.4)
Female outcome male exposure	552,516	0.7% (0.7–0.8)	1.5% (1.3–1.7)	2.6% (2.6–2.7)	8.6% (6.2–11.0)
Male outcome female exposure	552,516	0.1% (0.1–0.1)	0.3% (0.2–0.4)	4.2% (4.2–4.3)	8.4% (7.6–9.3)
Male outcome male exposure	582,900	0.1% (0.1–0.1)	0.2% (0.2–0.3)	4.1% (4.0–4.2)	10.6% (7.9–13.3)
Half-siblings	Pairsb
Both maternal and paternal	663,566	0.9% (0.8–0.9)	1.3% (1.2–1.3)	7.7% (7.6–7.8)	10.6% (9.9–11.4)

Notes: 95% CI 95% confidence intervals

^aCluster-robust standard errors based on mothers as clusters

^bNumber of unique ways of combining pairs, i.e., a pair may be included twice, first with A as outcome person and B as exposure person, then with B as outcome person and A as exposure person