Whether the addiction is behavioral (e.g., gambling, porn, shopping, gaming), or chemical (e.g., alcohol, marijuana, pills, or illegal drugs)-- addiction can cause a huge rift in your relationship. For many years, experts believed that only alcohol and powerful drugs could cause addiction. Neuroimaging technologies and more recent research, however, have shown that certain pleasurable activities, such as gambling, shopping, and sex, can also co-opt the brain.