Adolescents' screen time, sleep and mental health: literature review

Vernon 2018

Australia

Longitudinal cohort study

Follow-up: 1 year

N=1101

Age: 13-16 years

Baseline mean age: 13.5 years

Sex: 57% female

Ethnicity: 56.9%Caucasian, 7.1% Asian, 2% Aboriginal or Torres Strait Islander, 21.9% other

Other: 44% from lower SES

Night-Time Mobile Phone Use: Students were asked if they had a mobile phone and if they answered yes they were then asked, "At what time of the night do you usually send or receive messages and/or phone calls?" 6 response options: never text or phone after lights out; immediately after lights out; 10–11 p.m.; 11 p.m.–12 a.m.; 12–1 a.m.; 1–2 a.m.; 2–6 a.m.; at any time of the night. Coded on 6-point scale (0-5) as 0 = no mobile phone, 1 = never text or phone after lights out, 2 = immediately after lights out, 3 = before midnight, 4 = after midnight, and 5 = at any time of the night

Depressed mood: questionnaire

based on the mean of five items designed to tap emotional well-being, originally from the Michigan Study of Adolescent Life Transitions. Items included: "How often do you feel there is nothing nice you can look forward to; feel unhappy, sad, or depressed?" Responses ranged from 1 (never) to 6 (daily). Higher scores = worse outcome

Latent Growth Curve Mediation Models (Mediator: sleep quality; Covariate: bedtime, gender, SES)

Indirect effect intercept:

B=0.29 (95%CI 0.10 to 1.75) ß=0.44

Externalising behaviour: Questionnaire comprising the mean of seven items, included: "In the past 6 months how often have you skipped school without parent permission?; how often have you gotten in a physical fight with another person?" The items were

measured on an 8-point scale from 1 (none) to 8 (31 or more times), Higher scores = worse outcome

Latent Growth Curve Mediation Models (Mediator: sleep quality; Covariate: bedtime, gender, SES)

Indirect effect intercept:

B=0.08 (95%CI 0.01 to 1.34) ß=0.12

Self-esteem:

Questionnaire based on the mean for three items and included: "How often do you feel satisfied with who you are?" Items were measured on a 6-point scale from 1 (never) to 6 (daily). The items were reverse coded with higher scores = low self-esteem.

Latent Growth Curve Mediation Models (Mediator: sleep quality; Covariate: bedtime, gender, SES)

Indirect effect intercept:

B=0.13 (95%CI 0.04 to 0.73) ß=0.15

Coping:

Single-item question: "How often do you feel that you are capable of coping with most of your problems?" Responses ranged from 1 (never) to 6 (daily). The item was reverse coded with higher scores = poor coping ability

Latent Growth Curve Mediation Models (Mediator: sleep quality; Covariate: bedtime, gender, SES)

Indirect effect intercept:

B=0.16 (95%CI 0.06 to 1.07) ß=0.19

Vernon 2017

Australia

Longitudinal cohort study

Follow-up: 2 years

N=874

Age: range not reported

Baseline mean age: 14.4 years (SD not reported)

Sex: 59% female

Ethnicity: 57.2% were Caucasian, 7.2% Asian, and 1.6% Aboriginal or Torres Strait Islander, 23.3% other

Social media use assessed using the problematic use of social networking scale consisting of 4 items. Items measured the degree to which adolescents invest emotionally in social networking

• Item 1: "I prefer to spend time on Facebook/ Myspace/ Bebo rather than attend social activities/ events";
• Item 2: "I use Facebook/Myspace/Bebo as a way of making me feel good";
• Item 3: "I get into arguments with other people about the amount of time I spend on Facebook/ Myspace/Bebo."
• Item 4: "If I can't access Facebook/ Myspace/Bebo, I feel moody and irritable".

Possible responses ranged from 0 (no social media profile) to 1 (completely disagree) and 5 (completely agree).

Depressed mood:

See Vernon 2018

Latent Growth Curve Mediation Models (Mediator: sleep disruptions; Covariate: gender, SES, pubertal timing)

Indirect effect intercept:

B = 0.181 (95%CI 0.132 to 0.244)

Externalising behaviour:

See Vernon 2018

Latent Growth Curve Mediation Models (Mediator: sleep disruptions; Covariate: gender, SES, pubertal timing)

Indirect effect intercept:

B = 0.037 (95%CI 0.019 to 0.060)

Werner-Seidler 2019

Australia

pilot study (single arm pre-post intervention design)

Follow-up: 6 weeks

N=50 (baseline)

Age: 12 to 16 years

Baseline mean age: 13.71 (SD 1.35)

Sex: 66% female

Other: With mild insomnia; 94% born in Australia

Sleep Ninja App aiming to teach users about the importance of consistent sleep and wake times, and recommended bedtimes. The structure of the Sleep Ninja app includes six training lessons, a sleep tracking function, recommended bedtimes based on sleep guidelines, reminders to start a wind-down routine each night, a series of sleep tips and general information about sleep. Training sessions were delivered through a chat-bot format where the sleep ninja essentially acts as a sleep coach. Training sessions took approximately 5–10 min to complete.

Intervention duration: 6 weeks (locked sessions thereafter)

Depressive symptoms: Patient Health Questionnaire-Adolescent

Version (PHQ-A), asked about symptoms in preceding 2 weeks. Items scored on a 4-point scale, summed together to form a total depression score ranging from 0 to 24.

0–9 = minimal symptoms, 10–14 = mild symptoms, 15–19 = moderate symptoms, 20–24 = severe depression

Multilevel modelling, random effects

β=−2.60, p<0.001

Cohen's d =0.36

Anxiety: Generalised Anxiety Disorder 7-item scale (GAD-7), items scored on a scale from 0 (not at all) to 3 (nearly every day). Total score

ranging from 0 to 21: 0–4 = minimal anxiety, 5–9 = mild anxiety, 10–14= moderate anxiety,

15–21 = severe anxiety

Multilevel modelling, random effects

β=−2.56, p<0.001

Cohen's d =0.41