Table 4.

Prevalence of ASD by exposure, stratified by the duration of the last episode of depression before cohort entry, number of antidepressants prescribed during the last episode of depression before cohort entry, and the presence of anxiety and/or other psychiatric disorders

	ASD cases	Pregnancies	Prevalence per 1,000 pregnancies (95% CI)	Crude RR (95% CI)	Adjusted RRa (95% CI)
Duration of the last episode of depression
Unexposed	1,500	154,107	9.7 (9.3–10.2)	1.00 (reference)	1.00 (reference)
Untreated depression
<12 months	123	8,557	14.4 (12.0–17.1)	1.48 (1.23–1.77)	1.45 (1.20–1.75)
12–35.9 months	61	3,683	16.6 (12.8–21.1)	1.93 (1.59–2.33)	1.68 (1.29–2.18)
≥36 months	10	641	15.6 (7.9–27.8)	1.60 (0.86–2.99)	1.52 (0.81–2.84)
Unknown	2	113	17.7 (2.9–58.5)	1.82 (0.45–7.28)	1.51 (0.38–6.04)
Treated depression
<12 months	260	16,433	15.8 (14.0–17.8)	1.63 (1.43–1.85)	1.59 (1.38–1.83)
12–35.9 months	115	6,134	18.8 (15.6–24.2)	1.70 (1.32–2.20)	1.88 (1.54–2.30)
≥36 months	66	3,045	21.7 (16.9–27.4)	2.23 (1.74–2.85)	2.11 (1.63–2.74)
Unknown	5	166	30.1 (11.0–66.8)	3.09 (1.29–7.49)	2.90 (1.21–6.99)
Other indications for antidepressant use	12	1,615	7.4 (4.0–12.6)	0.76 (0.43–1.35)	0.74 (0.42–1.30)
Number of different antidepressants prescribed during the last episode of depression
Unexposed	1,500	154,107	9.7 (9.3–10.2)	1.00 (reference)	1.00 (reference)
Untreated depression
1	142	10,269	13.8 (11.7–16.3)	1.42 (1.20–1.69)	1.39 (1.16–1.67)
≥2	52	2,628	19.8 (14.9–25.8)	2.03 (1.54–2.68)	1.94 (1.46–2.57)
Unknown	2	97	20.6 (3.5–68.1)	b	b
Treated depression
1	293	18,161	16.1 (14.4–18.1)	1.66 (1.46–1.88)	1.62 (1.42–1.85)
≥2	146	7,463	19.6 (16.6–22.9)	2.01 (1.70–2.38)	1.91 (1.59–2.29)
Unknown	7	147	47.6 (20.8–94.2)	b	b
Other indications for antidepressant use	12	1,615	7.4 (4.0–12.6)	0.76 (0.43–1.35)	0.74 (0.42–1.30)
Anxiety/other psychiatric disorders
Unexposed
No anxiety/other psychiatric disorders	1,421	147,939	9.6 (9.1–10.1)	1.00 (reference)	1.00 (reference)
Anxiety/other psychiatric disorders	79	6,168	12.8 (10.2–15.9)	1.33 (1.06–1.67)	1.36 (1.09–1.72)
Untreated depression
No anxiety/other psychiatric disorders	127	8,655	14.7 (12.2–17.4)	1.53 (1.27–1.83)	1.58 (1.31–1.90)
Anxiety/other psychiatric disorders	69	4,339	15.9 (12.5–20.0)	1.66 (1.30–2.11)	1.74 (1.37–2.23)
Treated depression
No anxiety/other psychiatric disorders	283	17,282	16.4 (14.6–18.4)	1.70 (1.50–1.94)	1.76 (1.54–2.00)
Anxiety/other psychiatric disorders	163	8,496	19.2 (16.4–22.3)	2.00 (1.70–2.35)	2.08 (1.76–2.46)
Other indications for antidepressant use
No anxiety/other psychiatric disorders	6	1,127	5.3 (2.2–11.1)	0.55 (0.25–1.24)	0.56 (0.25–1.25)
Anxiety/other psychiatric disorders	6	488	12.3 (5.0–25.6)	1.28 (0.57–2.85)	1.33 (0.59–2.96)

Notes:

^aAdjusted for child sex, maternal BMI, smoking status, parity, anxiety, and other psychiatric disorders.

^bToo little data to calculate a stable estimate.

Abbreviations: ASD, autism spectrum disorder; BMI, body mass index.