Dependent behavior, such as drug abuse and eating disorders, are often connected with other mental health problems. The sequential process of these disordersshould be better understood in order to develop prevention programs and new treatments. This was the main aim of this research. In total, 308 adolescents and young adults aged 14 to 25 years (mean, 20.5 years) were included in the study. A semi-structured interview (The Mini-International Neuropsychiatrie Interview, M.I.N.I.), along with DSM-IV criteria, was used in order to evaluate longitudinally the different mental health disorders. Results show that the Major Depressive Episode was the most common comorbid disorder, followed by Separation Anxiety. The disorders appear in a large proportion of cases before, or simultaneously with, the dependent behavior.