ABSTRACT
Data Sets ........................................................................................................... 141 The Oregon Adolescent Depression Project (OADP) ................................. 141 The Adolescent Coping With Depression Course (CWD-A) ...................... 141 Making a Plan for Success (MAPS) ............................................................ 142 Treatment for Adolescents with Depression Study (TADS) ...................... 142
Epidemiology of Comorbidities ....................................................................... 142 MDD and Dysthymia ................................................................................... 142
Temporal Order ....................................................................................... 143 Impact ...................................................................................................... 143
MDD and Anxiety Disorders....................................................................... 144 Temporal Order ....................................................................................... 144 Impact ...................................................................................................... 144
MDD and Disruptive Behavior Disorders ................................................... 145 Temporal Order ....................................................................................... 145 Impact ...................................................................................................... 146
MDD and Substance Use Disorders ............................................................ 146 Temporal Order ....................................................................................... 147 Impact ...................................................................................................... 147
MDD and Eating Disorders.......................................................................... 147 Temporal Order ....................................................................................... 148 Impact ...................................................................................................... 148
Models of Comorbidity Causation .................................................................. 149 Using Family Studies to Examine Models of Comorbidity ....................... 149 Models of Comorbidity Between Depression and Substance Use
Disorders: An Illustration ....................................................................... 149 Self-Medication Model ............................................................................ 150 Affective Consequences Model .............................................................. 150 Independent Factors Model .................................................................... 150 Reciprocal Relations Model .................................................................... 151
Impact of Comorbidity on Treatment.............................................................. 151 Comorbidity Increases Treatment Utilization ........................................... 152 Comorbid Adolescents are More Depressed and
Impaired at Intake ................................................................................... 152 Comorbidity Decreases Engagement and Retention .................................. 152
Methods of Improving Engagement Given Comorbidity ........................... 153 Comorbidity Decreases Treatment Effectiveness in
Reducing Depression ............................................................................... 154 Comorbidity Increases the Risk of Depression Recurrence ...................... 155 Impact of Depression on Treatment of Other Conditions ......................... 156 An Intervention for One Disorder Treats Both Conditions ....................... 157 New Interventions Targeting Both Disorders ............................................ 159
Clinical Implications and Future Directions ................................................. 161 Implications for Assessment ....................................................................... 161 Implications for Treatment ......................................................................... 162 Implications for Prevention ........................................................................ 163 Implications for Theory ............................................................................... 163
References ........................................................................................................ 163
Psychiatric comorbidity can be defi ned as the co-occurrence of two or more disorders within a diagnostic system at rates that are higher than expected by chance. Comorbidity generally refers to either the lifetime (but not necessarily simultaneous) or concurrent co-occurrence of disorders. The issue of psychiatric comorbidity received a great deal of attention in the 1990s (e.g., Angold & Costello, 1993; Lewinsohn, Rohde, & Seeley, 1995; Nottelmann & Jensen, 1999; Rohde, Lewinsohn, & Seeley, 1991), and it is now generally recognized that comorbidity represents an important factor to consider in research and clinical decisions, although the empirical basis for understanding how to actually intervene effectively with comorbid depressed adolescents remains surprisingly limited.
