. 2022 Jun 16;33(6):1621–1651. doi: 10.1007/s00787-022-02012-8

Table 4.

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

Study	Sample characteristics	Mobile phone & wireless devices measure	Mental health measure	Key findings	Covariates controlled for	Quality assessment
Lemola, et al. [61] Switzerland	Total: 362 Mean age: 14.8 (SD = 1.3) 44.75% female	- Electronic media use in bed before sleep for the following activities: talking on the phone/texting in chat rooms or surfing the Internet. Measured with a 5-point Likert scale - MP type ownership (smartphone or phone with basic features)	Internalising: - Depressive symptoms: 6 items from the ADS-K (German version of CES-D)	Adolescents with smartphones are not significantly more likely to have depressive symptoms than those that have mobile phones with basic features only (F = 0.79, p = 0.37) Depressive symptoms are significantly correlated with calling/text messaging in bed (r = 0.18, p < 0.001) and with being online (Facebook, Chat etc.) in bed (r = 0.22, p < 0.001) Electronic media use in bed before sleep was related to higher levels of depressive symptoms (β = 0.26, t = 4.84, p < 0.001), shorter sleep on weekday nights (β = – 0.29, t = – 6.00, p < 0.001) and greater sleep difficulties (β = .21, t = 3.91, p < 0.001) The presence of sleep difficulties partially mediates relationship between electronic media use at night and depressive symptoms (from β = 0.26, t = 4.84, ΔR² = 0.060; p < 0.001 to β = 0.17, t = 3.49, ΔR² = 0.026; p < 0.001)	Sex, age, sleep behaviours	High risk of bias
Mei, et al. [58] China	Total: 3020 7th–11th grade students 49.21% female	- Frequency of MP use before bedtime (never/sometimes/often) - Daily duration of bedtime MP use before sleep - Which mode of MP was most time-consuming function out of following options: call, surfing the Internet, texting - Daily duration of above most time-consuming function	Internalising: - Depression: BDI-II - Anxiety: SAS	MP use before sleep associated with more depressive symptoms (β = 0.89, p < 0.001) and anxiety symptoms (β = 1.22, p < 0.001) Reduced sleep duration partially mediated this association (β reduced to 0.16 and 0.22 for anxiety and depression respectively, p < 0.001) Adolescents who often used MP before sleep, sleep duration was significantly shorter and sleep onset latency was significantly longer than adolescents who either sometimes or never used MP except to study (p < 0.05)	Age, sex, SES, BMI, parenting/family, neighbourhood, health condition, educational attainment, academic stress, smoking, alcohol, snoring, sleep behaviours	High risk of bias
Mireku, et al. [54] UK	Total: 6616 Mean age: - Males: 12.1 (SD = 0.6) - Females: 12 (SD = 0.5) 48.8% female	Screen-based media devices (SMBD) of MP, tablet, eBook reader, laptop, within 1 h before sleep	Wellbeing: - HRQoL: KIDSCREEN-10	Adolescents who used MP during night-time reported lower HRQoL compared to those who did not use MP during night-time (OR = – 0.84, 95% CI [– 1.44, – 0.024] and use in a dark room was associated with even lower KIDSCREEN-10 score (β = – 1.18, 95% CI [– 1.85, – 0.52]) compared to no use Association found between use of at least one SBMD and lower HRQoL (OR = – 1.15, 95% CI = [– 1.82, – 0.48])	Sex, age, SES, ethnicity, school type, BMI, second-hand smoking, alcohol, caffeine in sensitivity analysis)	High risk of bias
Oshima, et al. [28] Japan	Total: 17,920 Mean age: - Early Adolescents: 13.7 (SD = 0.9) - Late Adolescents: 16.6 (SD = 0.9) 50.41% female	Frequency of MP use after lights out measured with a 3-point Likert scale	Internalising: - Suicidal feelings: 1 item measured with a 3-point Likert scale for agreement of symptoms - Self-harm behaviours over previous year: 1 dichotomous item; If Yes subjects asked to described method Wellbeing: - Psychological Wellbeing measured with General Health Questionnaire-12. If scored > 4 categorized as poor mental health	Early adolescents (EA) and late adolescents (LA) using mobiles phones after lights out ‘almost every day’ were more likely to have poorer mental health (EA: OR = 1.65; 95% CI [1.43–1.92]; p < 0.001, LA: OR = 1.54; 95% CI [1.38–1.72]; p < 0.001) compared to those who did not use their mobile phones after lights out Adolescents using mobile phones use after lights out also more likely to have more suicidal feelings (EA: OR = 1.62; 95% CI [1.31–1.99]; p < 0.001, LA: OR = 1.22; 95% CI 1.04–1.42; p = 0.014) and more likely to experience self-injury (EA: OR = 1.56; 95% CI [1.12–2.17]; p = 0.009, LA: OR = 1.75; 95% CI [1.33–2.29]; p < 0.001) compared to those who did not use their mobile phones after lights out	Age, sex, alcohol, drug use and sleep behaviours	High risk of bias

Study

Sample characteristics

Mobile phone & wireless devices measure

Mental health measure

Key findings

Covariates controlled for

Quality assessment

Lemola, et al. [61]

Switzerland

Total: 362

Mean age: 14.8

(SD = 1.3)

44.75% female

- Electronic media use in bed before sleep for the following activities: talking on the phone/texting in chat rooms or surfing the Internet. Measured with a 5-point Likert scale

- MP type ownership (smartphone or phone with basic features)

Internalising:

- Depressive symptoms: 6 items from the ADS-K (German version of CES-D)

Adolescents with smartphones are not significantly more likely to have depressive symptoms than those that have mobile phones with basic features only (F = 0.79, p = 0.37)

Depressive symptoms are significantly correlated with calling/text messaging in bed (r = 0.18, p < 0.001) and with being online (Facebook, Chat etc.) in bed (r = 0.22, p < 0.001)

Electronic media use in bed before sleep was related to higher levels of depressive symptoms (β = 0.26, t = 4.84, p < 0.001), shorter sleep on weekday nights (β = – 0.29, t = – 6.00, p < 0.001) and greater sleep difficulties (β = .21, t = 3.91, p < 0.001)

The presence of sleep difficulties partially mediates relationship between electronic media use at night and depressive symptoms (from β = 0.26, t = 4.84, ΔR² = 0.060; p < 0.001 to β = 0.17, t = 3.49, ΔR² = 0.026; p < 0.001)

Sex, age, sleep behaviours

High risk of bias

Mei, et al. [58]

China

Total: 3020

7th–11th grade students

49.21% female

- Frequency of MP use before bedtime (never/sometimes/often)

- Daily duration of bedtime MP use before sleep

- Which mode of MP was most time-consuming function out of following options: call, surfing the Internet, texting

- Daily duration of above most time-consuming function

Internalising:

- Depression: BDI-II

- Anxiety: SAS

MP use before sleep associated with more depressive symptoms (β = 0.89, p < 0.001) and anxiety symptoms (β = 1.22, p < 0.001)

Reduced sleep duration partially mediated this association (β reduced to 0.16 and 0.22 for anxiety and depression respectively, p < 0.001)

Adolescents who often used MP before sleep, sleep duration was significantly shorter and sleep onset latency was significantly longer than adolescents who either sometimes or never used MP except to study (p < 0.05)

Age, sex, SES, BMI, parenting/family, neighbourhood, health condition, educational attainment, academic stress, smoking, alcohol, snoring, sleep behaviours

High risk of bias

Mireku, et al. [54]

Total: 6616

Mean age:

- Males: 12.1 (SD = 0.6)

- Females: 12 (SD = 0.5)

48.8% female

Screen-based media devices (SMBD) of MP, tablet, eBook reader, laptop, within 1 h before sleep

Wellbeing:

- HRQoL: KIDSCREEN-10

Adolescents who used MP during night-time reported lower HRQoL compared to those who did not use MP during night-time (OR = – 0.84, 95% CI [– 1.44, – 0.024] and use in a dark room was associated with even lower KIDSCREEN-10 score (β = – 1.18, 95% CI [– 1.85, – 0.52]) compared to no use

Association found between use of at least one SBMD and lower HRQoL (OR = – 1.15, 95% CI = [– 1.82, – 0.48])

Sex, age, SES, ethnicity, school type, BMI, second-hand smoking, alcohol, caffeine in sensitivity analysis)

High risk of bias

Oshima, et al. [28]

Japan

Total: 17,920

Mean age:

- Early Adolescents: 13.7 (SD = 0.9)

- Late Adolescents: 16.6 (SD = 0.9)

50.41% female

Frequency of MP use after lights out measured with a 3-point Likert scale

Internalising:

- Suicidal feelings: 1 item measured with a 3-point Likert scale for agreement of symptoms

- Self-harm behaviours over previous year: 1 dichotomous item; If Yes subjects asked to described method

Wellbeing:

- Psychological Wellbeing measured with General Health Questionnaire-12. If scored > 4 categorized as poor mental health

Early adolescents (EA) and late adolescents (LA) using mobiles phones after lights out ‘almost every day’ were more likely to have poorer mental health (EA: OR = 1.65; 95% CI [1.43–1.92]; p < 0.001, LA: OR = 1.54; 95% CI [1.38–1.72]; p < 0.001) compared to those who did not use their mobile phones after lights out

Adolescents using mobile phones use after lights out also more likely to have more suicidal feelings (EA: OR = 1.62; 95% CI [1.31–1.99]; p < 0.001, LA: OR = 1.22; 95% CI 1.04–1.42; p = 0.014) and more likely to experience self-injury (EA: OR = 1.56; 95% CI [1.12–2.17]; p = 0.009, LA: OR = 1.75; 95% CI [1.33–2.29]; p < 0.001) compared to those who did not use their mobile phones after lights out

Age, sex, alcohol, drug use and sleep behaviours

High risk of bias