Are subsyndromal symptomatic depression and major depressive disorder distinct disorders?

doi: 10.3969/j.issn.1002-0829.2012.05.006 Division of Mood Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China *correspondence: [email protected] Depressive conditions that do not meet full symptomatic or duration criteria for a major depressive disorder (MDD) are of considerable interest to both clinicians and researchers.[1-4] The fourth edition of the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) provides descriptions of several types of subthreshold depressive states including dysthymia, minor depression and recurrent brief depression; but many individuals with subthreshold depression and associated impaired functioning do not meet DSM-IV diagnostic criteria for any of these disorders.[3] To cover these cases Judd and colleagues[4] proposed the concept of ‘Subsyndromal Symptomatic Depression’ (SSD) for individuals without depressed affect or anhedonia who have two or more (but less than five) of the other seven symptoms of depression that have been present for most of the time for at least two weeks and that are associated with impaired social functioning.[3,4] The appropriate diagnosis and treatment of individuals with this type of subthreshold depression will require a better understanding of the relationship between SSD and MDD. Are they independent disorders or is SSD a transitional state on the road to MDD?