The role of poor mental health in substance use across socioeconomic strata of Armenian adolescents: a counterfactual mediation analysis

Figures & data

Figure 1. Possible pathways to socioeconomic disparities in substance use among Armenian adolescents. Dotted and solid lines represent the indirect and direct effects of family socioeconomic position on substance use, respectively.

Table 1. Adolescent characteristics (n = 6512 participants^a).

Factors	n	%
Age in years
11	2360	36.2
13	2192	33.7
15	1959	30.1
Sex
Boys	3102	47.6
Girls	3410	52.4
Family SEP
High	1762	29.3
Middle	2490	41.4
Low	1760	29.3
Mental health problems, mean (95% CI)^b,c	2.22 (2.19–2.25)
Smoking at present
No	6240	97.1
Yes	189	2.9
Beer, at least weekly
No	5680	94.1
Yes	356	5.9
Spirits, at least weekly
No	5672	96.9
Yes	179	3.1
Wine, at least weekly
No	5581	93.1
Yes	415	6.9
Lifetime cannabis, > 1–2 days^d
No	1720	99.0
Yes	18	1.0

SEP, socioeconomic position

a: Due to missing values, not all numbers sum up to 6512

b: score from 1 (low) to 10 (high)

c: geometric means are presented

d: only 15-year-old boys reported lifetime cannabis use for more than 1–2 days

Table 2. Adolescent characteristics by substance use.

Factors	Smoking at present		P-value	Beer, at least weekly		P-value		Spirits, at least weekly		P-value		Wine, at least weekly		P-value	Lifetime cannabis, > 1–2 days^a		P-value
	N	%		N	%			N	%			N	%		N	%
Age in years
11	39	1.7	< 0.001	121	5.6		< 0.001	59	2.8		0.566	150	7.0	0.183	-	-	-
13	52	2.4		94	4.6			58	3.0			124	6.2		-	-
15	98	5.1		141	7.6			62	3.4			141	7.7		1720	18
Sex
Boys	160	5.2	< 0.001	280	9.8		< 0.001	138	5.0		< 0.001	294	10.5	< 0.001	18	2.5	< 0.001
Girls	29	0.9		76	2.4			41	1.3			121	3.8		0	0.0
Family SEP
High	47	2.7	< 0.001	109	6.7		< 0.001	55	3.5		0.041	128	8.0	0.018	3	1.3	0.061
Middle	46	1.9		92	3.9			52	2.3			133	5.7		3	0.4
Low	69	4.0		103	6.2			54	3.4			112	6.8		9	1.6
Mental health problems score, mean difference (95% CI)^b	1.32 (1.21–1.46)		< 0.001	1.19 (1.11–1.28)			< 0.001	1.27 (1.15–1.40)			< 0.001	1.28 (1.21–1.36)		< 0.001	1.18 (1.01–1.18)		0.039

SEP, socioeconomic position; Bold values denote statistical significance (P < 0.05)

a: only 15-year-old boys reported lifetime cannabis use for more than 1–2 days

b: difference in geometric means are presented

Table 3. Linear regression coefficients (95% confidence interval) of mental health problems^a by family SEP, adjusted for age, sex, and survey round/year.

Factor	Estimated B^b	Estimated 95% CI	P-value
Family SEP
High		Reference
Middle	1.12	1.08–1.17	< 0.001
Low	1.36	1.31–1.42	< 0.001

SEP, socioeconomic position

Bold values denote statistical significance (P < 0.05)

a: the log-transformed score was used in the model

b: unstandardized regression coefficient

Table 4. Poisson regression coefficients (95% confidence interval) of substance use by mental health problems^a, adjusted for age, sex, family SEP and survey round/year.

Factor	B	95% CI	P-value
Smoking at present	1.01	0.65–1.36	< 0.001
Beer, at least weekly	0.69	0.42–0.95	< 0.001
Spirits, at least weekly	0.98	0.61–1.35	< 0.001
Wine, at least weekly	0.95	0.75–1.16	< 0.001
Lifetime cannabis, > 1–2 days^b	2.54	1.60–3.48	< 0.001

SEP, socioeconomic position; Bold values denote statistical significance (P < 0.05)

a: the log-transformed score was used in the model

b: only 15-year-old boys reported lifetime cannabis use for more than 1–2 days

Table 5. Prevalence ratios (95% confidence interval) of substance use by family SEP (adjusted for age, sex, survey round/year) and percentage mediated/suppressed by high/low mental health problems^a.

	Low vs. middle SEP^b		High vs. middle SEP
	PR (95% CI)	% mediated^c	PR (95% CI)	% suppressed^d
Smoking at present
NDE	1.63 (1.08–2.46)		1.77 (1.12–2.78)
NIE	1.18 (1.08–1.29)	25.6	0.87 (0.81–0.94)	23.8
Total effect	1.93 (1.29–2.88)		1.54 (0.98–2.42)
Beer, at least weekly
NDE	1.30 (0.94–1.80)		1.71 (1.22–2.41)
NIE	1.13 (1.05–1.21)	31.3	0.91 (0.86–0.95)	18.0
Total effect	1.46 (1.07–2.01)		1.55 (1.11–2.18)
Spirits, at least weekly
NDE	1.26 (0.82–1.95)		1.77 (1.15–2.75)
NIE	1.22 (1.11–1.35)	46.5	0.89 (0.83–0.95)	20.4
Total effect	1.54 (1.01–2.37)		1.58 (1.02–2.45)
Wine, at least weekly
NDE	0.90 (0.68–1.18)		1.51 (1.15–1.98)
NIE	1.19 (1.13–1.27)	-	0.88 (0.84–0.92)	31.3
Total effect	1.07 (0.82–1.40)		1.33 (1.01–1.75)
Lifetime cannabis, > 1–2 days^e
NDE	1.67 (0.46–6.10)		2.61 (0.45–15.15)
NIE	1.86 (1.34–2.56)	54.7	0.78 (0.57–1.08)	25.6
Total effect	3.10 (0.91–10.59)		2.04 (0.33–12.63)

NDE, natural direct effect; NIE, natural indirect effect

SEP, socioeconomic position; Bold values denote statistical significance (P < 0.05)

a: the log-transformed score was used in the models

b: the middle family SEP was taken as a reference category to have positive log-level estimates, considering the lowest prevalences of substance use in the middle-SEP group

c: the proportion mediated was calculated as log(NIE)/log(total effect)

d: the proportion suppressed was estimated as 1 – log(total effect)/log(NDE)

e: only 15-year-old boys reported lifetime cannabis use for more than 1–2 days

Data availability statement

The data that support the findings of this study are available in the HBSC Data Management Centre at https://www.uib.no/en/hbscdata/113290/open-access