Excessive use of the Internet is unhealthy for adolescents, even if they have never experienced psychological problems. A new study has found that addictive Internet use by teenagers can lead to depression and other behavioral problems, or can exacerbate preexisting conditions. Internet addiction, although not classified as an explicit psychological disorder in the current Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR), is being considered for inclusion in an upcoming publication in the DSM due to the disorder\u2019s rapid growth. Internet addiction is believed to be a disorder in and of itself due to its similar characteristics to other addiction disorders. On the other hand, compulsive use of the Internet may be an underlying symptom of more severe behavioral disorders. Prior research has found addictive Internet use to be attributed to several psychiatric problems, aggressiveness, withdrawal, and physical health problems in adult studies. However, not much research has been available on excessive Internet use by adolescents and its potential risks on mental health. Researchers at Australia\u2019s University of Notre Dame and Sydney\u2019s School of Medicine conducted a cohort study involving 1,041 random teenagers between the ages of 13 to 18 years from high schools throughout Guangzhou, China. Lead researcher Dr. Lawrence Lam and his team sought to discover the impact of excessive Internet use on adolescent mental health, particularly on risks of anxiety and depression. With the Pathological Use of the Internet Test, researchers surveyed students on their pathological Internet use and other addictive behaviors. Researchers also assessed the presence of depression and anxiety among student participants following the Zung Depression and Anxiety Scales. Initially, 6.2% of the participants were classified as displaying moderately pathological Internet use while 0.2% of participants were at severe risk of addiction. After a follow-up study nine months later, researchers had found that only 0.2% of participants displayed symptoms of anxiety, but 8.4% of participants had become depressed. While addictive Internet use was not found to be linked to anxiety in participants, the teenagers with Internet addiction problems were 2.5 times more likely to become depressed. The researchers conclude that teenagers who used the Internet at an excessive rate had a heightened risk of depression. Even teenagers who were considered to be mentally healthy were likely to develop depression after their prolonged excessive use of the Internet. Those teenagers who had a prior history of behavioral problems, such as depression, were likely to have their conditions worsened by the pathological Internet use. However, it wasn\u2019t clear whether the Internet addiction was the direct cause of their depression, or if individuals who are prone to depression are more likely to develop addictive behaviors, like Internet addiction. Individuals who suffer from depression, anxiety, stress, or other behavioral disorders may turn to the Internet as way to relieve their symptoms since the Internet offers an alternate way of coping with social anxiety and self-esteem in an isolated environment. In the U.S., the Substance Abuse and Mental Health Services Administration (SAMHSA) estimates that 9% of adolescents suffer from a major depressive episode each year. The development of process disorders, like Internet addiction, may indicate the existence of more serious behavioral problems in teenagers. As technology continues to evolve, so do the types of process disorders that are growing among adolescent groups. Dr. Lam and his team recommend that schools implement early intervention and prevention strategies that are aimed at identifying risk factors in students for behavioral problems like depression and Internet addiction. Students who are considered to be displaying symptoms of these disorders should be referred to counseling, the researchers suggest. Sources: Health Day,\u00a0Addictive Internet Use Tied to Depression in Teens, August 2, 2010 Archives of Pediatrics & Adolescent Medicine, Lawrence T. Lam, PhD, and Zi-Wen Pen, MSc, Effect of Pathological Use of the Internet on Adolescent Mental Health.