1. There are often underlying or co-occurring psychiatric disorders, such as anxiety, depression or a disturbance in interpersonal relationships, all of which may explain the person’s Internet problems,” Ronald W. Pies, a professor of clinical psychiatry at Tufts University told BusinessNewsDaily sister site LiveScience for a 2009 article. “The question is, do we need another ‘disorder’ in the APA’s Diagnostic and Statistical Manual of Mental Disorders (DSM), if the manifestations of Internet addiction can already be accounted for by well-described and better-validated conditions?