How do people become addicted to the Internet?

To relieve unpleasant and overwhelming feelings

Many people turn to the Internet in order to manage unpleasant feelings such as stress, loneliness, depression, and anxiety. When you have a bad day and are looking for a way to escape your problems or to quickly relieve stress or self-soothe, the Internet can be an easily accessible outlet. Losing yourself online can temporarily make feelings such as loneliness, stress, anxiety, depression, and boredom evaporate into thin air. As much comfort as the Internet can provide, though, it’s important to remember that there are healthier (and more effective) ways to keep difficult feelings in check. These may include exercising, meditating, using sensory relaxation strategies, and practicing simple breathing exercises. 
For many people, an important aspect of overcoming Internet and computer addiction is to find alternate ways to handle these difficult feelings. Even when your Internet use is back to healthy levels, the painful and unpleasant feelings that may have prompted you to engage in unhealthy Internet use in the past will remain. So, it’s worth spending some time thinking about the different ways you intend to deal with stressful situations and the daily irritations that would normally have you logging on.

Risk factors for Internet addiction and computer addiction

You are at greater risk of Internet addiction if:

• You suffer from anxiety. You may use the Internet to distract yourself from your worries and fears. An anxiety disorder like obsessive-compulsive disorder may also contribute to excessive email checking and compulsive Internet use.
• You are depressed. The Internet can be an escape from feelings of depression, but too much time online can make things worse. Internet addiction further contributes to stress, isolation and loneliness.
• You have any other addictions. Many Internet addicts suffer from other addictions, such as drugs, alcohol, gambling, and sex.
• You lack social support. Internet addicts often use social networking sites, instant messaging, or online gaming as a safe way of establishing new relationships and more confidently relating to others.
• You’re an unhappy teenager, you might be wondering where you fit in and the Internet might feel more comfortable than real life friends.
• You are less mobile or socially active than you are used to. For example, you may be coping with a new disability that limits your ability to drive. Parenting very young children can make it hard to leave the house or connect with old friends.
• You are stressed. While some people use the Internet to relieve stress, it can have a counterproductive effect. The longer you spend online, the higher your stress levels will be.