Compr Psychiatry. 2016 Oct;70:41-52. doi: 10.1016/j.comppsych.2016.06.011. Epub 2016 Jun 16.
Internet addiction (IA) is a risk factor while some psychosocial factors can be protective against depression among adolescents. Mechanisms of IA onto depression in terms of mediations and moderations involving protective factors are unknown and were investigated in this study.
A representative cross-sectional study was conducted among Hong Kong Chinese secondary school students (n=9518).
Among males and females, prevalence of depression at moderate or severe level (CES-D≥21) was 38.36% and 46.13%, and that of IA (CIAS>63) was 17.64% and 14.01%, respectively. Adjusted for socio-demographics, depression was positively associated with IA [males: adjusted odds ratio (AOR)=4.22, 95% CI=3.61-4.94; females: AOR=4.79, 95% CI=3.91-5.87] and negatively associated with psychosocial factors including self-esteem, positive affect, family support, and self-efficacy (males: AOR=0.76-0.94; females: AOR=0.72-0.92, p<.05). The positive association between IA and depression was partially mediated by the protective psychosocial factors (mainly self-esteem) across sexes. Through significant moderations, IA also reduced magnitude of protective effects of self-efficacy and family support among males and that of positive affect among both sexes against depression.
The high IA prevalence contributes to increased risk of prevalent depression through its direct effect, mediation (reduced level of protective factors) and moderation (reduced magnitude of protective effects) effects. Understanding to mechanisms between IA and depression through protective factors is enhanced. Screening and interventions for IA and depression are warranted, and should cultivate protective factors, and unlink negative impact of IA onto levels and effects of protective factors.
EXCERPTS FROM DISCUSSION SECTION
Our findings suggest that IA contributed to the high prevalence of probable depression among secondary school students in Hong Kong. About one sixth of the sampled students had IA. The sex difference was statistically significant but was only mild, with prevalence of IA among males about 4% higher than that among female
IA was strongly associated with probable depression at moderate level or above levels (OR N 4). The results corroborate with those obtained from several cross-sectional studies [30,32,68] and those of two longitudinal studies showing that heavier Internet use predicted development of depression a year later [34,35]. Interventions reducing IA may hence reduce risk of depression among secondary school students.
Importantly, another longitudinal study showed that depression assessed at baseline predicted new IA incidence during the follow-up period among Taiwanese adolescents . The relationship between IA and depression among students is hence likely to be bi-directional, and a vicious cycle might be in operation [19,33].
The mechanism between IA and depression is not well understood. There is a dearth of studies looking at related mediators; one study suggested that mediators included frequency of stressful events such as corporal punishment by parents, examination failure, breaking up with a close friend and serious illness, as assessed by Adolescent Self-Rating Life Events Checklist . To our knowledge, there is no study investigating protective factors as mediators of the association between IA and depression. We found partial mediations of about 60% altogether for all the four psychosocial protective factors, and 6.3% to 48.5% for single psychosocial protective factor, with self-esteem being the key mediator in both sexes. It is not a surprise to find partial but not full mediation, as other mediators that are risk factors of both depression and IA (e.g., conflict with family members) may exist but were not included in this study. We contended that IA reduced level of protective factors, and the weakened protection from these factors in turn increased one’s vulnerability to develop depression