In this series, I dig a little deeper into the meaning of psychology-related terms. This week’s term is atypical depression.
“Atypical features” is a specifier that describes individual depressive episodes. While the name suggests it’s not particularly common, that’s not actually the case. The atypical name comes because of the way it differs from depression with melancholic features.
Symptoms of atypical depression
In addition to meeting the criteria for a major depressive episode, the atypical features specifier requires the first of the following symptoms as well as at least two others:
- mood reactivity to pleasurable stimuli or positive events
- increased appetite or significant weight gain (as opposed to decreased appetite and weight loss in melancholic features)
- increased sleep (as opposed to early morning awakening in melancholic features)
- feeling of heaviness in the limbs that has a significant impact on functioning (aka leaden paralysis)
- a pattern of longstanding sensitivity to interpersonal rejection
In the world of psychiatry, the term “neurovegetative symptoms” refers to depression’s impact on sleep, appetite, and weight. The increased sleep and appetite with atypical features is sometimes referred to as reversed neurovegetative symptoms (i.e. a reversed pattern from melancholic features).
Atypical features first showed up in the DSM with the release of the DSM-IV back in 1994. There’s been a fair bit of debate around the criteria and whether it constitutes a distinct illness from melancholic depression. While the DSM requires mood reactivity for an atypical features diagnosis, some researchers have argued against that.
One figure I came across said that between 15-29% of patients with depression have atypical features. It’s particularly common in people with bipolar II disorder and persistent depressive disorder (formerly known as dysthymia). Atypical features are more common in females, and the age of onset tends to be younger than in people with other presentations of depression. Almost 2/3 of people who have atypical features in a given depressive episode have a repeat of atypical features in their next episode.
People with atypical features are more likely to have a history of sexual abuse or neglect (research results are less clear re. physical abuse) versus those with non-atypical features. They’re also more likely to experience suicidal thinking and suicide attempts, as well as greater functional disability.
People with atypical features are more likely to have comorbid conditions, and in particular panic disorder, social anxiety disorder, or bulimia, compared to people with non-atypical depression. Rates of substance abuse are also higher.
While melancholic depression often involves a hyperactive stress hormone system (the hypothalamic-pituitary-adrenal axis), that’s not the case in atypical depression, and an underactive HPA axis has been observed in some patients with reversed neurovegetative symptoms. Differences in blood perfusion to certain areas of the brain have been observed in atypical vs non-atypical depression.
Treatment specific to atypical features hasn’t been as well researched as treatment of melancholic features. Monoamine oxidase inhibitor (MAOI) antidepressants are about twice as effective as tricyclic antidepressants (TCAs) in this patient population. However, MAOIs are more likely to cause side effects and require limiting dietary tyramine intake, so they’re not generally used as a first-line treatment. Fluoxetine has shown positive results in some fairly small studies. Bupropion (Wellbutrin) may be a good first-line choice; it affects the neurotransmitters norepinephrine and dopamine rather than serotonin and tends to be more activating than SSRIs.
People with atypical features don’t appear to respond as well to electroconvulsive therapy (ECT) as people with melancholic depression. In terms of psychotherapy, cognitive behavioural therapy (CBT) has been found to be effective.
I’ve always tended toward melancholic features, and I’ve never had atypical features with my own depression. When my sleep and appetite are affected, they’re always decreased rather than increased.
Is atypical depression something that you’ve ever experienced?
- Cristancho, M. A., O’reardon, J. P., & Thase, M. E. (2011). Atypical depression in the 21st century: Diagnostic and treatment issues. Psychiatric Times, 28(1), 42-47.
- Łojko, D., & Rybakowski, J. K. (2017). Atypical depression: Current perspectives. Neuropsychiatric Disease and Treatment, 2017(13), 2447-2456.
- Matza, L. S., Revicki, D. A., Davidson, J. R., & Stewart, J. W. (2003). Depression with atypical features in the National Comorbidity Survey: Classification, description, and consequences. Archives of General Psychiatry, 60(8), 817-826.
- Nelson, E. B., & McElroy, S. L. (2003). Atypical depression Puzzled? How to piece together symptoms and treatments. Current Psychiatry, 2(4), 13.
The Psychology Corner has an overview of terms covered in the What Is… series, along with a collection of scientifically validated psychological tests.
Ashley L. Peterson
BScPharm BSN MPN
Ashley is a former mental health nurse and pharmacist and the author of four books.