Fertility history and use of antidepressant medication in late mid-life: a register-based analysis of Norwegian women and men

Figures & data

Table 1. Distribution of women and men in the study population (born in 1935–1959 and alive at the beginning of 2004 and end of 2008) by variables used in the analysis and number of women and men in the study population who purchased medicine for depression at least once during the years 2004–2008.

	Women		Men
	Proportion in different categories (%)	Number of persons purchasing depression medicine	Proportion in different categories (%)	Number of persons purchasing depression medicine
Year of birth
1935–1939	13.3	17,407	11.9	7979
1940–1944	17.0	21,193	16.6	11,381
1945–1949	22.7	30,618	23.2	18,204
1950–1954	22.7	30,922	23.4	18,628
1955–1959	24.3	31,148	24.9	18,987
Education
10 years	27.7	45,031	24.1	23,087
11 years	32.3	42,184	24.3	19,016
12–13 years	14.3	17,688	21.9	15,313
14–17 years	22.6	23,620	20.7	13,366
18+ years	3.2	2765	9.0	4397
Marital status
Never married	8.3	6771	13.3	11,342
Married	66.4	78,568	68.5	45,963
Widowed	6.5	9373	1.7	1475
Divorced/separated	18.7	32,576	16.5	16,399
Number of children, age at first birth
0 child	9.7	12,754	14.2	12,346
1 child, low	2.5	4321	2.3	2099
1 child, medium	3.1	4831	2.8	2252
1 child, high	6.9	9273	6.9	5337
2 children, low	11.5	18,173	12.0	9785
2 children, medium	14.7	18,968	12.9	8660
2 children, high	14.3	14,975	13.2	8382
3 children, low	10.1	15,936	10.2	8176
3 children, medium	9.8	11,393	8.4	5456
3 children, high	5.8	5550	5.8	3583
4+ children, low	6.0	9130	6.0	5253
4+ children, medium	4.0	4436	3.5	2442
4+ children, high	1.6	1549	1.8	1409
	Total number under study		Total number under study
	6,30,513	1,31,288 (20.8%)	6,28,277	75,179 (12.0%)

Note: For women, low age at first birth is below 22, medium is 22–25, and high is above 25; for men, low age at first birth is below 25, medium is 25–28, and high is above 28.

Table 2. Associations (with 95% confidence intervals) between number of children and parent's age at first birth and odds of using medicine for depression at least once during 2004–2008, among women and men aged 45–69 in 2004 (i.e. born in 1935–1959).

Women	Model 1	Model 2 (for the parous)	Model 3 (for the parous)
Number of children
0 child	1
1 child	1.13*** (1.11–1.16)	1	1
2 children	0.97** (0.95–0.99)	0.86*** (0.84–0.88)	0.81*** (0.80–0.83)
3 children	0.95*** (0.93–0.97)	0.84*** (0.83–0.86)	0.76*** (0.75–0.78)
4+ children	0.94*** (0.92–0.97)	0.83*** (0.81–0.85)	0.72*** (0.70–0.74)
Age at first birth
−19			1.37*** (1.34–1.40)
20–21			1.17*** (1.15–1.19)
22–25			1
26–28			0.87*** (0.86–0.89)
29+			0.85*** (0.83–0.87)
Men	Model 1	Model 2 (for the parous)	Model 3 (for the parous)
Number of children
0 child	1
1 child	0.96*** (0.93–0.98)	1	1
2 children	0.84*** (0.82–0.86)	0.88*** (0.86–0.90)	0.86*** (0.84–0.88)
3 children	0.85*** (0.83–0.87)	0.89*** (0.87–0.91)	0.85*** (0.83–0.88)
4+ children	0.96** (0.93–0.99)	1.00 (0.97–1.03)	0.94*** (0.91–0.97)
Age at first birth
−22			1.23*** (1.20–1.26)
23–24			1.08*** (1.05–1.11)
25–28			1
29–32			0.98* (0.95–1.00)
33+			0.99 (0.96–1.02)

*p < 0.10; ** p < 0.05; *** p < 0.01.

Note: It was controlled for age and education.

Table 3. Association (with 95% confidence intervals) between number of children and parent's age at first birth and odds of using medicine for depression at least once during 2004–2008, among women and men aged 45–69 in 2004 (i.e. born in 1935–1959).

Women
Number of children, age at first birth
0 child	1	1	1
1 child, low	1.28*** (1.23–1.34)	1.20*** (1.15–1.25)	1.17*** (1.12–1.22)
1 child, medium	1.21*** (1.16–1.26)	1.15*** (1.11–1.20)	1.14*** (1.10–1.19)
1 child, high	1.05*** (1.01–1.08)	1.02 (0.99–1.06)	1.04** (1.01–1.07)
2 children, low	1.18*** (1.15–1.21)	1.15*** (1.12–1.18)	1.14*** (1.11–1.17)
2 children, medium	0.97** (0.95–0.99)	0.97** (0.94–1.00)	0.98 (0.95–1.01)
2 children, high	0.81*** (0.79–0.83)	0.82*** (0.80–0.85)	0.85*** (0.82–0.87)
3 children, low	1.16*** (1.13–1.19)	1.14*** (1.11–1.18)	1.13*** (1.09–1.16)
3 children, medium	0.87*** (0.84–0.89)	0.88*** (0.86–0.91)	0.89*** (0.87–0.92)
3 children, high	0.74*** (0.72–0.77)	0.77*** (0.74–0.80)	0.79*** (0.77–0.82)
4 children, low	1.09*** (1.06–1.13)	1.07*** (1.03–1.11)	1.05*** (1.02–1.09)
4 children, medium	0.82*** (0.79–0.85)	0.84*** (0.80–0.87)	0.85*** (0.81–0.88)
4 children, high	0.74*** (0.70–0.78)	0.78*** (0.73–0.82)	0.80*** (0.75–0.85)
Marital status
Never married		1.10*** (1.07–1.13)
Married		1
Widowed		1.21*** (1.18–1.24)
Divorced/separated		1.58*** (1.55–1.60)
Marital status
Never married			1.16*** (1.13–1.19)
Married, definitely experienced disruption			1.47*** (1.43–1.50)
Married, other			1
Widowed			1.26*** (1.23–1.30)
Divorced/separated			1.66*** (1.63–1.69)
Men
Number of children, age at first birth
0 child	1	1	1
1 child, low	1.05** (1.00–1.11)	1.04 (0.99–1.09)	1.03 (0.97–1.08)
1 child, medium	0.95* (0.91–1.00)	0.95** (0.90–1.00)	0.94** (0.89–0.99)
1 child, high	0.92*** (0.89–0.95)	0.93*** (0.89–0.96)	0.93*** (0.90–0.97)
2 children, low	0.93*** (0.91–0.96)	0.96** (0.93–1.00)	0.96** (0.93–1.00)
2 children, medium	0.81*** (0.79–0.83)	0.84*** (0.81–0.87)	0.85*** (0.80–0.85)
2 children, high	0.78*** (0.76–0.80)	0.81*** (0.79–0.84)	0.83*** (0.80–0.85)
3 children, low	0.93*** (0.90–0.96)	0.96** (0.93–1.00)	0.95*** (0.92–0.98)
3 children, medium	0.79*** (0.77–0.82)	0.83*** (0.80–0.86)	0.83*** (0.80–0.87)
3 children, high	0.76*** (0.73–0.80)	0.81*** (0.77–0.84)	0.82*** (0.78–0.85)
4 children, low	1.02 (0.98–1.05)	1.04* (1.00–1.08)	1.00 (0.96–1.04)
4 children, medium	0.86*** (0.82–0.90)	0.90*** (0.86–0.94)	0.88*** (0.84–0.93)
4 children, high	0.96 (0.91–1.02)	1.02 (0.96–1.09)	1.02 (0.96–1.08)
Marital status
Never married		1.14*** (1.11–1.27)
Married		1
Widowed		1.31*** (1.24–1.39)
Divorced/separated		1.47*** (1.44–1.50)
Marital status
Never married			1.18*** (1.15–1.22)
Married, definitely experienced disruption			1.28*** (1.25–1.32)
Married, other			1
Widowed			1.36*** (1.28–1.44)
Divorced/separated			1.53*** (1.50–1.56)

*p < 0.10; **p < 0.05; ***p < 0.01.

Notes: For women, low age at first birth is below 22, medium is 22–25, and high is above 25; for men, low age at first birth is below 25, medium is 25–28, and high is above 28. It was controlled for age and education. Among women, 66% of the exposure time was in the married category (see Table 1); 7% was in the sub-category ‘definitely experienced disruption’ and 59% were in the ‘other’ sub-category. The corresponding proportions for men were 69%, 9% and 60%.

Table 4. Association (with 95% confidence intervals) between number of children and parent's age at first birth and odds of using medicine for depression at least once during 2004–2008, among women and men who were born in 1935–1959 and who were registered in the data with at least one maternal sibling of the same sex also born 1935–1959 (i.e. a sample of sibling sets consisting of two or more maternal same-sex siblings born in 1935–1959).

Women	Model without control for sibling fixed effects	Models with control for sibling fixed effects
Number of children, age at first birth
0 child	1	1	1
1 child, low	1.27*** (1.18–1.36)	1.15** (1.03–1.27)	1.12** (1.01–1.25)
1 child, medium	1.19*** (1.11–1.28)	1.16*** (1.05–1.28)	1.16*** (1.04–1.29)
1 child, high	1.02 (0.96–1.07)	0.98 (0.91–1.07)	1.00 (0.92–1.08)
2 children, low	1.12*** (1.07–1.18)	1.05 (0.97–1.12)	1.07* (0.99–1.16)
2 children, medium	0.93*** (0.89–0.98)	0.91*** (0.85–0.98)	0.95 (0.88–1.02)
2 children, high	0.78*** (0.74–0.82)	0.80*** (0.75–0.86)	0.85*** (0.78–0.91)
3 children, low	1.13*** (1.08–1.19)	1.05 (0.98–1.13)	1.08* (0.99–1.17)
3 children, medium	0.85*** (0.80–0.89)	0.86*** (0.80–0.93)	0.91 (0.83–0.99)
3 children, high	0.71*** (0.66–0.75)	0.70*** (0.64–0.77)	0.76*** (0.69–0.83)
4+ children, low	1.07** (1.01–1.13)	0.98 (0.90–1.07)	1.01 (0.92–1.11)
4+ children, medium	0.77*** (0.71–0.82)	0.77*** (0.69–0.85)	0.81*** (0.72–0.91)
4+ children, high	0.66*** (0.54–0.74)	0.62*** (0.53–0.73)	0.68*** (0.58–0.80)
Marital status
Never married			1.20*** (1.12–1.28)
Married			1
Widowed			1.28*** (1.18–1.38)
Divorced/separated			1.57*** (1.50–1.63)
Men	Model without control for sibling fixed effects	Models with control for sibling fixed effects
Number of children, age at first birth
0 child	1	1	1
1 child, low	1.07* (0.99–1.16)	1.05 (0.93–1.18)	1.07 (0.95–1.21)
1 child, medium	0.95 (0.88–1.03)	0.89** (0.80–1.00)	0.91 (0.81–1.03)
1 child, high	0.92*** (0.87–0.97)	0.90*** (0.82–0.97)	0.92* (0.85–1.01)
2 children, low	0.92*** (0.87–0.96)	0.88*** (0.81–0.94)	0.94 (0.86–1.01)
2 children, medium	0.81*** (0.77–0.85)	0.83*** (0.78–0.89)	0.89*** (0.82–0.96)
2 children, high	0.76*** (0.72-0.79)	0.79*** (0.74–0.84)	0.85*** (0.78–0.91)
3 children, low	0.92*** (0.88–0.97)	0.93* (0.87–1.00)	1.00 (0.92–1.08)
3 children, medium	0.76*** (0.72–0.81)	0.80*** (0.74–0.87)	0.87*** (0.79–0.95)
3 children, high	0.71*** (0.67–0.75)	0.78*** (0.71–0.85)	0.84*** (0.76–0.93)
4+ children, low	0.97 (0.92–1.03)	0.95 (0.87–1.04)	1.01 (0.91–1.11)
4+ children, medium	0.75*** (0.69–0.81)	0.73*** (0.65–0.82)	0.79*** (0.70–0.89)
4+ children, high	0.75*** (0.67–0.84)	0.76*** (0.65–0.89)	0.82*** (0.70–0.97)
Marital status
Never married			1.21*** (1.13–1.29)
Married			1
Widowed			1.45*** (1.24–1.68)
Divorced/separated			1.41*** (1.34–1.48)

*p < 0.10; **p < 0.05; ***p < 0.01.

Notes: For women, low age at first birth is below 22, medium is 22–25, and high is above 25; for men, low age at first birth is below 25, medium is 25–28, and high is above 28. It was controlled for age and education. There were 188,620 women in the study population (38,395 of whom purchased antidepressants) and 235,835 men (27,150 of whom purchased antidepressants).