Atypical depression

Atypical depression
Other namesDepression with atypical features
Atypical depression diagram.png
Depression subtypes
SpecialtyPsychiatry, psychology
SymptomsLow mood, mood reactivity, hyperphagia, hypersomnia, leaden paralysis, interpersonal rejection sensitivity
ComplicationsSuicide
Usual onsetTypically adolescence[1]
TypesPrimary anxious, primarily vegetative[1]
Risk factorsBipolar disorder, anxiety disorder, female sex[2]
Differential diagnosisMelancholic depression, anxiety disorder, bipolar disorder
Frequency15-29% of depressed patients[3]

Atypical depression as it has been known in the DSM IV, is depression that shares many of the typical symptoms of the psychiatric syndromes of major depression or dysthymia but is characterized by improved mood in response to positive events. In contrast, people with melancholic depression generally do not experience an improved mood in response to normally pleasurable events. Atypical depression also features significant weight gain or an increased appetite, hypersomnia, a heavy sensation in the limbs and interpersonal rejection sensitivity that results in significant social or occupational impairment.[4]

Despite its name, "atypical" depression does not mean it is uncommon or unusual.[5] The reason for its name is twofold: (1) it was identified with its "unique" symptoms subsequent to the identification of melancholic depression and (2) its responses to the two different classes of antidepressants that were available at the time were different from melancholic depression (i.e., MAOIs had clinically significant benefits for atypical depression, while tricyclics did not).[6]

Atypical depression is two to three times more common in women than in men.[4] Individuals with atypical features tend to report an earlier age of onset (e.g. while in high school) of their depressive episodes, which also tend to be more chronic[7] and only have partial remission between episodes. Younger individuals may be more likely to have atypical features, whereas older individuals may more often have episodes with melancholic features.[4] Atypical depression has high comorbidity of anxiety disorders, carries more risk of suicidal behavior, and has distinct personality psychopathology and biological traits.[7]Atypical depression is more common in individuals with bipolar I,[7] bipolar II,[7][8] cyclothymia[7] and seasonal affective disorder.[4] Depressive episodes in bipolar disorder tend to have atypical features,[7] as does depression with seasonal patterns.[9]

Signs and symptoms

The DSM-IV-TR defines Atypical Depression as a subtype of Major Depressive Disorder with Atypical Features, characterized by:

  1. Mood reactivity (i.e., mood brightens in response to actual or potential positive events)
  2. At least two of the following:
    • Significant weight gain or increase in appetite (hyperphagia);
    • Hypersomnia (sleeping too much, as opposed to the insomnia present in melancholic depression);
    • Leaden paralysis (i.e., heavy feeling resulting in difficulty moving the arms or legs);
    • Long-standing pattern of interpersonal rejection sensitivity (not limited to episodes of mood disturbance) that results in significant social or occupational impairment.
  3. Criteria are not met for With Melancholic Features or With Catatonic Features during the same episode.