Table 3.

General use of mobile phones and/or wireless devices: cross-sectional findings

Study	Sample characteristics	Mobile phone & wireless devices measure	Mental health measure	Findings of interest	Covariates controlled for	Quality assessment
Calpbinici and Arslan [15] Turkey	Total: 426 Mean age: 16.05 (SD = 1.26) 49.5% female	- Daily duration of MP calls categorized into “none, ≤ 1 h, > 1 h” - Purpose of MP usage (talking/messaging, social media)	Internalising: - Anxiety and depression symptoms: subscales from Brief Symptom Inventory (BSI) Externalising: - Hostility: subscale from BSI Wellbeing: - Negative Self‐esteem subscale from BSI	No significant difference between groups with daily speaking duration with regards any of the BSI subscales Adolescents who used MP more social media had significantly higher BSI mean for every subscale (p < .001)	None	High risk of bias
Foerster and Röösli [46] Switzerland	Total: 412 Mean age: 14.1 (Range 10.4–17.0) 56.9% female	Specific use of MP during weekend and weekdays: calls (minutes/day), text messages (f/day), online on MP (m/day), social networking. Categorised into “low, medium, high”	Wellbeing: - Health-Related Quality of Life (HRQoL): KIDSCREEN-52	Latent class analysis of MP use, general media use, and MPPUS-10 scores identified 5 distinct classes: Low Use, Medium Use, Gaming, Call Preference and High Social Use Significant difference in HRQoL found across groups in Physical Wellbeing (p = 0.002), Moods & Emotions (p < 0.001), Self-Perception (p > 0.001), Self-perception (p < 0.001), Parent Relations & Home Life (p < 0.001), Social Support & Peers (p < 0.001) & School Environment (p < 0.007). For the other four scales (Psychological Wellbeing, Autonomy, Financial Resources, Social Acceptance) no significant differences between the classes were found	Sex, age, SES, ethnicity, educational attainment	High risk of bias
George, et al. [45] USA (cross-sectional findings only)	Total 151 Mean age: 13.1 (SD = 0.91) 48% female	Hours spent texting and text messages sent by MP using ecological momentary assessment (EMA)	Internalising: - Depressive Symptoms: 5 dichotomous items from the Beck Depression Inventory (BDI) - Anxiety symptoms: 4 dichotomous items from the Multidimensional Anxiety Scale for Children Externalising: - ADHD symptoms: 4 dichotomous items adapted from the DSM–IV symptom checklist - CD symptoms: 6 dichotomous items from DSM–IV and Child Behaviour Checklist *all measures modified for EMA	Adolescents reported fewer anxiety (p = 0.007; incident rate ratio (IRR) = 0.99) and fewer depression symptoms (p = 0.006, IRR = 0.99) on days where they sent more text messages Association found between time on mobile phone texting and reduced anxiety symptoms, (b = 0.05 95% CI [0.09, 0.01] p < 0.05), but with increased risk of conduct disorder (b = 0.22 95% CI [0.10, 0.33] p < 0.001) and with increased risk of ADHD (b = 0.10 95% CI [0.04, 0.18] p < 0.01) No association found between duration of texting and depressive symptoms	MH baseline	High risk of bias
Guxens, et al. [52] Netherlands	Total: 3102 Mean age: 5 Female: not reported	Parent-reported frequency of MP and cordless phone calls	Internalising & Externalising: - Mother & teacher-reported Strengths & Difficulties Questionnaire (SDQ): Total Difficulties & all subscales. Subjects categorized in normal, borderline, and abnormal	MP use for category < 1call/week had lower odds of teacher-reported total difficulties SDQ borderline/abnormal score when compared with no MP use (OR = 0.67, CI = [0.47–0.95]), but not for mother-reported total difficulties MP use for category < 1call/week had smaller risk of mother-reported peer relationship SDQ borderline/abnormal score than those with no use (OR = 0.61, CI = [0.42–0.91]) Children with cordless phone at home had lower odds of teacher-reported borderline/abnormal prosocial behaviour (OR = 0.68, CI = [0.48–0.97]) and lower odds of mother-reported peer relationship problems (OR = 0.61, 95% CI = [0.39–0.96]) No other teacher- or mother-reported SDQ subscales was significantly associated with cordless/MP phone calls Null result found when testing for trend between cordless/MP use and SDQ total difficulties score	Sex, age, SES, family/parenting, Maternal factors (education, ethnicity, BMI tobacco, alcohol, MH, attachment)	High risk of bias
Hosokawa and Katsura [51] Japan	Total: 1642 Mean age: 6.88 (SD = 0.35 years) Female:48.8%	Parent-reported average typical daily duration of smartphone and tablet use. Categorized into “regular and non-regular users”	Internalising & Externalising: - Parent-reported SDQ. Subjects categorized into normal, borderline, abnormal	Regular mobile device uses significantly associated with higher externalizing problems, specifically conduct problems (OR: 1.77, 95% CI: [1.03 ± 3.04], p < .05) and hyperactivity /inattention (OR: 1.82, 95% CI: [1.15 ± 2.87], p < .01) Regular mobile device uses not significantly associated with internalizing problems	Sex, SES, parenting/family, baseline MH	High risk of bias
Ikeda and Nakamura [10] Japan	Total: 2698 First-years: 45.9% Second-years: 48.9 Third-years: 5.2% Female: 62.3%	Average mean duration of MP use per week and per weekday and then stratified by quartiles	Internalising: - 4 subcomponents (“Tension and excitement,” “Refreshing mood” “Depressed mood”, “Anxious mood.”) from the Mood Inventory	Increased duration of MP use per week is associated with lower psychological mood, for tension and excitement (p < 0.001), and particularly depressed mood (p < 0.009). For males, total scores for ‘‘Depressed mood,’’ and ‘‘Tension and excitement,’’of the highest quartile of weekly MP use were significantly higher than for other quartiles (p < 0.05) No association between MP use and mood scores was found in female subgroup	Sex, age, school type, physical activity, previous MP-use, sleep behaviours	High risk of bias
Mortazavi, et al. [16] Iran	Total: 469 Mean age: 11 (SD = 2.33) 49.89% female	Daily average duration of MP use for talking. Categorized into 4 groups: “No Use, Less than 10 min, 11–30 min, more than 30 min”	Internalising: - Anxiety: 1 item Externalising: - Concentration problems:1 item - Attention problems: 1 item All items measured by 4-point Likert scale for frequency of symptoms	Association between the duration of MP use when talking and self-reported symptoms of concentration problems (p < 0.001), attention problems (p < 0.001) and anxiety (p < 0.001) were found in students who had used MPs compared to those who had never used phones	None	High risk of bias
Nishida, et al. [12] Japan	Total: 295 Mean age: 16.2 (SD = 0.9) 41.4% female	Daily duration of type of smartphone use including email, social networking sites, online chat, internet search and watching videos	Internalising: - Depression: - Centre for Epidemiological Studies Depression (CES-D). Classified as depressed if score > 16	No association between general smartphone use and depression among male students OR = 1.09, CI = [0.65–1.82] or females student OR = 1.58, CI = [0.95–2.63]) Stratified analysis by gender showed Increased duration of online chat (OR = 1.7, CI = [1.18–2.56]), and SNS (OR = 1.41, 95% CI = [1.04–1.92]) using smartphone was associated with depression among female students, but not in males (OR = 1.09, 95% CI = [0.65–1.82]) p:0.737	Sex, age, educational attainment, lifestyle, sleep behaviours, parenting/family	High risk of bias
Przybylski and Weinstein [59] England	Total: 120,115 Mean age:15 (SD not reported) Female: Not reported	Daily duration of smartphones for social networking and chatting during free time on weekdays and weekend with categories	Well-being: - Psychological Well-being: Warwick-Edinburgh Mental Well-Being Scale	Inverted-U-shape relationship between digital-screen time, smartphones and mental WB. Moderate engagement not harmful and may be advantageous. Optimum / extremum for weekday smartphone use is 1 h 57 min; optimum/extremum for weekend smartphone use is 4 h 10 min Effect size of weekday smartphone use on WB above extremum is b = – 0.53, 95% CI [– 0.56, – 0.49] Cohen’s d = – 0.20 Effect size of weekend smartphone use on WB above extremum is b = – 0.83, 95% CI [– 0.94, – 0.74] Cohen’s d = – 0.14	Sex, SES, ethnicity, technology access	High risk of bias
Redmayne, et al. [14] New Zealand	Total: 373 Mean Age: 12.3 (Range: 10.4–13.7) 44.2% female	Frequency (number and duration) of cordless and MP use and type of MP headset. Cordless phone operating frequency, modulation system/approach	Internalising symptoms: - Depressive symptoms: 1 item from the Health Behaviour in School-aged Children checklist measured by a 4-point Likert scale for frequency of symptoms	Authors were not able to fit valid models with exposure variables of duration of cordless phones and MP calls, i.e. they could not determine if duration or frequency of use of wireless devices were associated with depressive symptoms Use of wired (OR = 0.90 [0.51–1.58]) or wireless (OR = 2.04 [1.09–3.82]) MP headsets was associated with frequency of depressive symptoms. Cordless phone frequency also associated with depressive symptoms, but only for frequencies ≤ 900 MHz (OR = 2.40 [1.15–5.02])	Sex, age, SES, woken by phone, illness, earpiece, headset, TV in bedroom	High risk of bias
Roser, et al. [47] Switzerland	Total: 412 Mean age: 14.0 (Range 12.1–17.0) 61.4% female Cohort: HERMES	Self-report: - Frequency of outgoing/incoming calls - Frequency of outgoing text messages and duration of data traffic Data from MP operators: - Frequency of outgoing/incoming calls - Outgoing SMS and the volume of data traffic over previous 6 months	Internalising &Externalising: - Parent & self-reported SDQ: Well-being: - HRQoL: KIDSCREEN-52	Ten-point increase in MPPUS-10 score was positively associated with β = 0.96 total difficulty score (95% CI [0.58, 1.35] p < 0.001). Positive association also found with hyperactivity (β = 0.42, 95% CI [0.26, 0.57]), conduct problems (β = 0.30, 95% CI [0.19, 0.41]) emotional symptoms (β = 0.17, 95% CI [0.02, 0.32]). Prosocial behaviour was significantly negatively associated with MPPUS-10 (β = – 0.14, 95% CI [– 0.25, – 0.04]) Six out of the ten HRQOL dimensions were significantly decreased (Moods and emotions, Self-perception, Autonomy, Parent relations and home life, Financial resources and School environment) in adolescents with higher MPPUS-10 score	Sex, age, SES (educational level of parents), school level, nationality, self-reported freq of text messages sent	High risk of bias
Tamura, et al. [11] Japan	Total: 295 Mean age: 16.2 (SD = 0.9) 41.4% female	Daily duration of type of smartphone use including email, social networking sites, online chat, internet search and watching videos	Internalising: - Depression: CES-D. Classified as depressed if score > 16	Mobile phone use of ≥ 2 h per day for social network services (OR: 3.63, 95% CI [1.20–10.98]) and online chats (OR: 3.14, 95% CI [1.42–6.95]), was associated with a higher risk of depression, even when adjusting for sleep duration	Sex, age, school type, lifestyle, sleep behaviours, lifestyle, parenting/family	High risk of bias