The Internet is everywhere these days. Or at least it seems to be. With over three billion current users (nearly half the world's population) and more likely to come online in the years to come, the prospect of universal Internet access doesn't seem that far away any more. For adolescents in particular, the rise of the modern Internet has transformed how they interact with friends, family, and strangers around the world.

Still, with all the advantages that the Internet can bring, there is also a dark side that many parents, teachers, and health professionals often find disturbing. Can adolescents develop mental health problems due to spending too much time online? There seem to be a glut of different clinical terms used to describe problem Internet behavior these days. Whether it is called "Internet addiction disorder," "Internet addiction,"or "Internet compulsion," some adolescents find themselves unable to stay off the Internet for long and experience problems in real-life social and academic functioning as a result.

While Internet addiction lacks many of the physical symptoms linked to drug or alcohol addiction, adolescents can still develop a psychological dependence on online activities. When their access to the Internet is cut off for any reason, they can experience a form of withdrawal as well as being unable to function normally without regular online contact. Researchers have also linked compulsive Internet use to a range of mental health concerns including low self-esteem, loneliness, depression, social phobia, and even suicidal thoughts.

One question that is still not being answered though is exactly why this link between compulsive Internet use and mental health issues exists. Is too much Internet use leading to these problems or are emotionally troubled adolescents simply more likely to become psychologically dependent on the Internet? While most research studies looking at mental health and Internet use tend to be one-time surveys with little real insight into cause and effect, there have still been a few longitudinal studies exploring how problem Internet use this can relate to emotional problems.

In one recent study looking at problem Internet use in adolescents between 13 and 17 years of age, results suggested that compulsive Internet use and depression mutually reinforce each other. Spending too much time on the Internet appears to predict later depression and other emotional problems which, in turn, led to increased Internet use. Other studies showed that social anxiety, low self-esteem, hostility, and even ADHD can lead to Internet addiction in many adolescents. But would researchers get the same results if they followed these adolescents over a number of years?

A new report published in the journal Developmental Psychology provides a more comprehensive look at how compulsive Internet use and mental health problems can be related. A team of Australian researchers led by Joseph Ciarrochi of Australian Catholic University conducted two studies to test different models linking Internet use and emotional problems. The research was also intended to examine how different types of Internet activity could be linked to social anxiety or depression.

In the first study, over two thousand students were followed from eighth to eleventh grade (the sample was roughly split between boys and girls). All participants completed inventories measuring different aspects of mental health as well as providing demographic information about family background. They also completed a specialized questionnaire designed to measure compulsive Internet use with items such as "Do you find it difficult to stop using the Internet while you are online?" “Do others (e.g., parents, brothers or sisters, friends) say you should use the Internet less?” “Are you short of sleep because of the Internet?” and "Do you feel restless, frustrated, or irritated when you cannot use the Internet?" This scale has already been found to be highly reliable in previous studies.

Results of the first study indicated that compulsive Internet use apparently leads to poorer mental health over the four years of the study. On the other hand, there was no indication that this relationship worked in reverse or that adolescents with mental health problems became addicted to the Internet. The years from eighth grade to eleventh grade seem to be especially important with increased Internet use leading to significantly greater mental health problems. This link between Internet use and mental health appeared to be the same for both males and females.

The second study looked at different kinds of online activities and how they might be linked to developing compulsive Internet behaviour. A sample of 687 adolescents in tenth and eleventh grade (350 males, 327 females, 10 unreported) completed the same measures of mental health and compulsive Internet use as in the first study. They also completed the Internet Behavior Questionnaire to see how often they engaged in specific Internet activities such as seeking information (Googling), using Facebook or Twitter, playing online games, using email, conducting online chats, visiting adult sites, etc.

As expected, there were significant differences between males and females in the kind of Internet activities they preferred. Males were more likely than females to play games and visit adult sites while females were more interested in social activities such as email and Twitter. Both males and females appear equally vulnerable to Internet compulsion though.

Based on their research results, Ciarrochi and his co-authors suggest that becoming addicted to the Internet is an "equal opportunity problem" that can strike all adolescents regardless of sex or family background. While there was some indication that spending too much time with instant messaging, or using Facebook and Twitter, can lead to mental health problems, the risk seems highest for adolescents in tenth grade.

These results don't necessarily mean that using the Internet frequently will always lead to compulsive use or that web-surfing adolescents will automatically develop mental health problems. Even though there does appear to be a causal link between compulsive Internet use and problems such as depression or social anxiety, the size of this relationship seems modest at best. Concerned parents and teachers should probably look at other risk factors first before worrying if an adolescent is spending too much time online.

Still, more research is definitely needed to look at how social phobia and loneliness can lead to compulsive Internet use or whether other factors can explain why compulsive Internet use can lead to mental health problems (such as loss of sleep for example). Programs for treating compulsive Internet use can also be developed using research like this to identify the best strategies for educating young people on problem behaviors that can lead to poorer mental health.

So what does this research suggest to parents worrying about their own children? While the simplest solution may be to crack down on how much time children are spending online, this is often counterproductive for many adolescents. One study looking at parents who get tough with their children regarding the Internet found that this actually increases compulsive Internet use rather than decreases it. A better strategy may simply be to talk to children in a way that makes them feel that they are being taken seriously and understood. It also helps to focus on how they're using the Internet rather than just how much time they're spending online.

While avoiding the Internet completely is probably impossible for most adolescents, it's important to understand that going online should never replace the kind of social interaction that we all need to be fully human. Using the Internet to escape real-life problems such as bullying or poor grades can often lead to greater problems down the line. As more and more of our modern life is moving towards greater use of the Internet, we all need to recognize that it can be used in positive or negative ways. Much like any other potentially addictive activity, it's important to do things in moderation.

Romeo Vitelli Ph.D, Psychology Today