Pathologic Internet Use by Teens Linked to Increased Depression Risk

Pam Harrison

August 03, 2010

August 3, 2010 — Young people who are initially free of mental health problems but who use the Internet pathologically are at risk for depression as a consequence of their addictive Internet use, new research suggests.

Lawrence Lam, PhD, School of Medicine, Sydney, and the University of Notre Dame, Fremantle, Australia, and colleagues performed a prospective study in which they showed that students who used the Internet pathologically at baseline were 2.3 times as likely to experience depression at 9-month follow-up compared with students who did not exhibit pathologic Internet use.

"After adjusting for potential confounding factors, the relative risk for depression for those who used the Internet pathologically was two and half times...that of the group who did not," they write. After taking baseline risk for controls into account, those who used the Internet pathologically were 1.5 times more likely to have experienced depression at follow-up than controls, they add.

In contrast, pathologic Internet use did not affect the risk of anxiety among the same survey cohort.

The study was published online August 2 in the Archives of Pediatrics & Adolescent Medicine.

"There are many possible explanations for the link between pathological Internet use and depression — one obvious explanation being lack of sleep, which is very common among problematic Internet users," Dr. Lam told Medscape Medical News. Young people may also be more "reactive" toward the contents of the Internet, particularly those who are involved in "gaming," he added.

"A lot of these games are highly competitive and mostly the players are playing against other competitors, [so] failure in game-playing is as real as failure in other parts of their lives," said Dr. Lam. "But these are only educated hypotheses; we still need much further research into possible reasons or explanation."

Primary Use for Entertainment

The study was performed on a sample of 1618 students who were attending high school in Guangzhou, Southeast China, in July 2008. The sample consisted mainly of adolescents between the ages of 13 and 16 years, with a mean age of 15 years. There was an even distribution between males and females and between urban and nonurban schools, although more families resided in the city (73%).

Anxiety was measured using the Zung Self-rating Anxiety Scale, depression by the Zung Self-rating Depression Scale, and pathologic use of the Internet by the Internet Addiction Test, also known as Young's Internet Addiction Scale. The Internet Addiction Scale contains questions that reflect typical behaviors of addiction, including, "How often do you feel depressed, moody, or nervous when you are off-line, which goes away once you are back on-line?"

Results showed that most respondents (93.6%) were "normal" Internet users, whereas 6.2% exhibited "moderate" pathologic use. Only 2 users (0.2%) of the cohort exhibited severely pathologic Internet use.

Approximately half of respondents (45.5%) used the Internet for entertainment, whereas about 28% used the Internet for information and knowledge and roughly similar numbers to communicate with school mates, making friends, and avoiding boredom.

"Young people who used the Internet pathologically were more likely to use it for entertainment and less likely to use it for information, and at the 9-month follow-up, 8 students (0.2%) were classified as having significant anxiety symptoms and 87 (8.4%) scored higher than the cutoff of 50 on the depression scale."

Table. Adjusted Ratio Ratios (95% CIs) of Anxiety and Depression

Pathologic Internet Use Anxiety Depression
Severe/moderate 1.0 (0.2 – 6.8) 2.5 (1.3 – 4.3)
Normal 1.0 1.0

CI = confidence interval

Mental Health Implications

According to the study authors, findings from the study have important preventive mental health implications for young people. According to a recent meta-analysis, screening at-risk adolescents can be effectively performed in the school setting, and a number of screening instruments for depression have already been used in many studies — suggesting that schoolchildren can be successfully screened for early signs of depression. Those who are identified as "at risk" for depression on initial screening then may go on to receive a clinical diagnosis and treatment, said Dr. Lam.

"Early intervention and prevention that targets at-risk groups with identified risk factors is effective in reducing the burden of depression among young people," the investigators write.

Internet Research Still in Its Infancy

Dimitri Christakis, MD, MPH, University of Washington, Seattle, told Medscape Medical News that research on problematic Internet use is still in its infancy in part because science has not been able to keep up with all of the various forms of activities that keep people on line.

"That said, there is growing evidence that pathological Internet use is a real entity...somewhat like problematic gambling, another form of nonpharmacological behavioral addiction, and as we see in problematic gambling, there is a link between problematic Internet usage and mental health," he said.

However, that link is almost certainly not unidirectional when it comes to pathologic Internet use but rather a "vicious cycle" where problematic Internet use increases social isolation and withdrawal, which leads to even more problematic Internet use, etc.

"People who are susceptible to depression are already more prone to social isolation and withdrawal and therefore more likely to develop problematic Internet usage because the Internet provides an outlet for them," Dr. Christakis observed. "So the findings from the study are highly plausible, and because it was longitudinal and adjusted for baseline levels of depression and Internet use, the findings are both novel and robust."

The study authors and Dr. Christakis have disclosed no relevant financial relationships.

Arch Pediatr Adolesc Med. Published online August 2, 2010.


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