title: Treatment resistant depression and axis I co-morbidity.
abstract: BACKGROUND
  Treatment resistant depression (TRD) continues to present a formidable challenge to clinicians, accounts for over half of the annual costs associated with treatment for depression and causes great frustration to patients. Although there have been studies attempting to define TRD, little information is available as to the cause of TRD. One suggestion is that patients with TRD have a greater frequency of co-morbid psychiatric disorders, which explains their resistance to standard antidepressant treatments. The objective of this study was to compare the co-morbidity of Axis I disorders between a sample of TRD patients and a sample of non-TRD patients.
  
  
  METHODS
  TRD and non-TRD patients, recruited from two separate antidepressant treatment studies, were assessed for Axis I co-morbidity using the SCID-P for the DSM-III-R. Patients for the two samples were then matched for baseline HAM-D-17 total score and gender.
  
  
  RESULTS
  Results reveal that non-TRD patients had a higher rate of both lifetime and current generalized anxiety disorder co-morbidity than did the TRD patients. No other statistically significant differences in Axis I co-morbidity were found.
  
  
  CONCLUSIONS
  These findings do not support the idea that current or lifetime Axis I co-morbidity is more common in TRD than non-TRD patients. In fact, the only statistical difference showed non-TRD patients with higher co-morbidity rates.
authors.affiliation: Depression Clinical and Research Program, Massachusetts General Hospital, Boston 02114, USA.
authors.forename: T
authors.initials: T
authors.lastname: Petersen
authors.forename: J A
authors.initials: JA
authors.lastname: Gordon
authors.forename: A
authors.initials: A
authors.lastname: Kant
authors.forename: M
authors.initials: M
authors.lastname: Fava
authors.forename: J F
authors.initials: JF
authors.lastname: Rosenbaum
authors.forename: A A
authors.initials: AA
authors.lastname: Nierenberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use*; D001008:Anxiety Disorders / Q000453:epidemiology*; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000188:drug therapy* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales
chemical_list: D000928:Antidepressive Agents