Table 1.

Socio-demographic and clinical characteristics of adolescent patients.

Variable	Total		Non IAD		IAD
	( N = 1,454)		( N = 1,000)		( N = 454)		Univariate analyses
	N	%	N	%	N	%	χ2	df	P
Gender (male)	564	38.8	434	43.4	130	28.6	28.67	1	<0.001
Rural residence	642	44.2	462	46.2	180	39.6	5.44	1	0.02
Only child status	584	40.2	403	40.3	181	39.9	0.02	1	0.88
Major medical conditions	74	5.1	53	5.3	21	4.6	0.29	1	0.59
Primary psychiatric diagnosis							30.56	3	<0.001
MDD	759	52.2	479	47.9	280	61.7
BD	123	8.5	85	8.5	38	8.4
ADHD	70	4.8	61	6.1	9	2.0
Others	502	34.5	375	37.5	127	28
Perceived academic pressure							26.08	2	<0.001
Low	212	14.6	159	15.9	53	11.7
Fair	717	49.3	523	52.3	194	42.7
High	525	36.1	318	31.8	207	45.6
Relationship with parents							77.70	2	<0.001
Good	537	36.9	435	43.5	102	22.5
Fair	695	47.8	454	45.4	241	53.1
Poor	222	15.3	111	11.1	111	24.4
Concern with COVID-19							22.17	2	<0.001
Very concerned	360	24.8	276	27.6	84	18.5
Moderately concerned	800	55.0	549	54.9	251	55.3
No or minimal concern	294	20.2	175	17.5	119	26.2
Daily physical exercise							22.76	2	<0.001
<30 min/day	1,062	73.0	693	69.3	369	81.3
30–60 min/day	297	20.4	233	23.3	64	14.1
More than 60 min/day	95	6.5	74	7.4	21	4.6
Mass media use for COVID-19							2.642	2	0.267
No or very few	477	32.8	315	31.5	162	35.7
Sometimes	660	45.4	460	46	200	44.1
Often	317	21.8	225	22.5	92	20.3
Difficulty seeing psychiatrists during COVID-19 pandemic							9.40	2	0.009
No or very few	1,146	78.8	797	79.7	349	76.9
Sometimes	264	18.2	182	18.2	82	18.1
Often	44	3.0	21	2.1	23	5.1
Treatment adherence during COVID-19 pandemic							39.35	2	<0.001
Poor	529	36.4	330	33.0	199	43.8
Fair	187	12.9	108	10.8	79	17.4
Good treatment adherence	738	50.8	562	56.2	176	38.8
Illness relapse in COVID-19							85.65	2	<0.001
No	656	45.1	520	52.0	136	30.0
Symptom worsening, but no relapse	519	35.7	343	34.3	176	38.8
Relapse	279	19.2	137	13.7	142	31.3
Guardians' personal income (RMB3000 and above/mon)	942	64.8	654	65.4	288	63.4	0.53	1	0.47
	Mean	SD	Mean	SD	Mean	SD	t/Z	df	P
Age (years)	14.73	1.94	14.76	2.00	14.65	1.78	1.01	1,452	0.32
PHQ-9 Total	8.51	8.52	5.19	6.88	15.83	7.12	−22.12	–a	<0.001
IAT Total	41.21	19.17	30.13	8.97	65.61	11.56	−63.64	1,452	<0.001

^aMann-Whitney U test; Bolded values: <0.05; COVID-19, coronavirus disease 2019; MDD, major depressive disorder; BD, bipolar disorder; ADHD, attention deficit hyperactivity disorder; PHQ-9, the 9-item patient health questionnaire; IAT, internet addiction disorder; SD, standard deviation.