TABLE A1.

Results multinomial regression, membership class 1 (n = 1419)

	Class 1: Variably high problematic SMU, variably high SMU frequency (ref. = class 4: persistently low problematic SMU, variably high SMU frequency)
	Model A			Model B			Model C			Model D			Model E (Figure 4)
	B	SE	OR	B	SE	OR	B	SE	OR	B	SE	OR	B	SE	OR
Controls
Girl (ref. = boy)	0.445*	.192	1.560	0.376	.213	1.457	1.190***	.257	3.288	0.643**	.203	1.903	1.174***	.289	3.241
Pre‐vocational education (ref. = pre‐university)	1.319***	.340	3.741	1.256***	.337	3.511	1.501**	.439	4.489	1.259***	.350	3.523	1.445**	.433	4.250
Intermediate education (ref. = pre‐university)	0.482	.364	1.619	0.314	.360	1.369	0.696	.464	2.006	0.453	.372	1.573	0.499	.455	1.649
Immigrant background (ref. = non‐immigrant)	−0.002	.225	0.998	0.071	.239	1.074	0.112	.264	1.120	−0.045	.233	0.956	0.100	.279	1.108
Subjective well‐being
Life satisfaction				−1.530***	.298	0.218							−1.349***	.331	0.263
Self‐esteem				0.098	.331	1.115							0.638	.441	1.940
Self‐control
Attention deficit							1.341***	.356	3.875				1.050**	.399	2.914
Impulsivity							1.599***	.338	4.972				1.607***	.393	5.051
Social competencies
Perceived friendship competence										−1.296***	.328	0.276	−0.210	.415	0.824

Abbreviations: B, logit coefficient; OR, odds ratio; Ref., reference category; SE, standard error; SMU, social media use.

^* p < .05

^** p < .01

^*** p < .001.