Table 1.

Characteristics of included studies (alphabetic order)

Author (year of publication), country	Age range (years)	PUI type	ADHD Group n Age mean years (SD) Male/female	Control Group n Age mean years (SD) Male/female Type of control group	Instrument/parameter (informant)	Results used for meta-analysis ADHD group M (SD) compared to control group M (SD)
Basgul et al. (2020) Turkey	10–13	Gaming	n = 100 11.53 (1.03) 82m/18f	n = 100 11.83 (0.98) 60m/40f Non-clinical	Scale: Computer Game Addiction Scale for Children (CGASC); Time: Daily total playing time (hr) (SR)	PUI- Scale (score): ADHD group 28.65 (9.19) > Control group 20.94 (7.37) PUI-Time (hr): ADHD group ∼1.82 (1.08), Control group ∼1.53 (0.90)a)
Bourchtein et al. (2019) USA	12–14	Technology use	n = 162 13.17 (0.41) 105m/57 f School sample, but regular diagnostic procedure for ADHD	n = 140 13.18 (0.40) 62m/78f Non-clinical	Time: Total media time (min.) (PR) or rated on a 6-point Likert scale (SR)	PUI-Time (min) (PR): ADHD group 177.07 (114.35) > Control group 136.16 (72.33) PUI-Time (Likert scaled score) (SR): ADHD group 7.08 (4.17) > Control group 5.93 (2.69)
Çakmak and Gul (2017) Turkey	12–16	Internet use	n = 34 13.50 (1.41) 23m/11f	n = 36 13.50y (1.42) 23m/13f Non-clinical	Scale: Online Cognition Scale (OCS) (PR); Time: Weekly internet use (hr per week))(PR)	PUI-Scale (score): ADHD group 132 (38.67) > Control group 89.72 (26.87) PUI-Time (hr per week) ADHD group 15.73 (14.36) (hr per day =2.24 (2.05)) > Control group 7.66 (6.90) (hr per day = 1.09 (0.98))
Gul et al., (2018) Turkey	13–19	Facebook overuse and addiction	n = 187 14.9 (1.7) 95/92	n = 102 14.9 (1.4) 50/52, Clinical control (first referral, non-ADHD)	Scale: Bergen Facebook Addiction Scale (BFAS) (SR)	PUI-Scale (score): ADHD group 40.4 (18.0) > Control group 27.9 (12.2)
Huang et al. (2020) Taiwan	9–12	Smartphone addiction	n = 61 10.64 (1.00) 50m/11f	n = 241 11.08 (0.81) 114m/127f Non-clinical	Scale: Smartphone Addiction Proneness scale (SAPS) adapted for parents (PR)	PUI-Scale (score): ADHD group 35.59 (9.48) > Control group 31.36 (8.91)
Izmir et al. (2019) Turkey	13–17	Internet addiction	n = 60 15.10 (1.86) Combined n = 25 Inattentive n=25 Hyperactive/impulsive n=10	n = 60 14.31 (2.23) No information on gender no ADHD; no other psychiatric diagnosis (/non-clinical/clinical?)	Scale: Internet Addiction Diagnostic Questionnaire (IADQ) Young (1998) (SR)	PUI-Scale (score): ADHD total group 59.41 (6.19)b) > Control group16.60 (5.62)
Kietglaiwansiri and Chonchaiya (2018) Thailand	6–19	Video game use	n = 80 ∼9.83 (2.96) 65m/15f	n = 102 ∼10.0 (1.48) 51m/51f Non-clinical	Scale: Game Addiction Screen-ing Test (GAST); Time: PC time (PR)	PUI-Scale (score): ADHD group ∼17.0 (12.5) > Control group ∼11.08 (10.55) PUI-Time: Weekday PC time (hr) ADHD group ∼2.03 (1.43) > Control group ∼1.53 (1.23)
Luş and Eroğlu (2019) Turkey	12–17	Internet addiction	n = 100 12–14y n=69 15–17y n=30 78m/21f	n = 95 12–14y n=51 15–17y n=44 34m/61f Non-ADHD clinical control (first referral)	Scale: Young Internet Addiction Scale (IAT) (SR)	PUI-Scale (score): ADHD group 30.97 (17.74) > Control group 26.37 (13.85)
Mazurek and Engelhardt (2013) USA	8–18	Video Game use	n = 44 11.10 (2.40) 44m/0	1. n = 41, 12.20 (1.40) 41m/0, Non-clinical 2. n = 56, 11.70 (2.20) 56/0, ASD	Scale: Problem Video Game Playing Test (PVGT, King et al. 2011) adapted for parents (PR); Time: Video Game time, hr day−1 (PR)	PUI-Scale (score) ADHD group 37.70 (9.20) > Control group 29.60 (7.10); ASD group 41.2 (12.7) > Control group 29.60 (7.10) PUI-Time (hr): ADHD group 1.70 (1.10) = Control group 1.20 (0.90); ASD group 2.1 (1.3) > Control group 1.20 (0.90)
Párraga et al. (2019) Spain	6–16	Video game playing	n = 80 10.10 (2.39) 55m/25f	n = 80 9.78 (2.38) 31m/49f Non-clinical	Time: Questionnaire about the child's lifestyle habits: Playing video game time (hr day−1) (PR).	PUI-Time (hr): ADHD group 0.21 (0.40) < Control group 0.52 (0.72)
Razjouyan et al. (2020) Iran	Elementary school children	Internet addiction (video game addiction)	n = 99 No information on age mean 66m/33f	n = 99 No information on age mean approx.50m/50f Non-clinical	Scale: Young's Internet Addiction Test (YIAT) (SR)	PUI-Scale (score): ADHD group 47.56 (13.43) > Control group 33.62 (14.09)
So et al. (2017) Japan	12–15	Internet addiction	n = 24 14m/10f No information on mean age	1. ASD: n = 83; 54m/29f 2. ADHD+ASD: n = 25; 15m/10f	Scale: YIAT Time: internet time (hr) rated on 3-point-Likert scale (SR)	PUI-Scale (score): ADHD group 42.7 (19.1) = ASD group 45.2 (17.3) PUI-Time (hr): ADHD group ∼1.89 (1.51) = ASD group ∼1.79 (1.40)
Thoma et al. (2020) Germany	8–18	Screen based media use (time)	n = 61 12.93 (2.13) 38m/23f	n = 61; 2.97 (2.22) 38m/23f Non-clinical	Time: Total media use schooldays (min). Screen time-based sedentary behavior questionnaire (Rey-López et al., 2012); (SR)	PUI-Time (min): ADHD group 275.2 (227.4) > Control group 167.7 (161.3)
Weinstein et al. (2015) Israel	13–15	Internet addiction (video game addiction)	n = 50 13.75 (0.80) 50/0 Special school students with formal diagnosis of ADHD	n = 50 14.0 (0.60) 50/0 Special school students, non-ADHD	Scale: Young's Internet Addiction Test (IAT) Time: hours spent on internet per day (4-point Likert scale) (SR)	PUI-Scale (score): ADHD group 2.93 (1.06) > Control group 2.22 (0.65) PUI-Time (hr): ADHD group ∼3.14 (2.35) > Control group ∼2.08 (1.54)

Notes: PR =Parent rating, SR= Self rating; ASD: Autism Spectrum Disorder. M= mean, SD= standard deviation. Estimated time data (based on recoded scores) or transformed values are indicated by ∼. “ADHD group > control group” indicates significantly higher PUI values in ADHD, “ADHD group < control group” indicates significantly lower PUI values in ADHD group; “ADHD group = Control group” indicates no significant difference. ^a) not statistically compared. ^b) ADHD score calculated from 3 subtype scores. Studies are listed in alphabetic order of authors.