Bipolar Depression is the depressive phase of Bipolar Disorder, where there is cycling between mania, depression, and sometimes mixed episodes. This is in contrast to Unipolar Depression (Major Depressive Disorder), where there is only depressive episodes, with no manic episodes. Bipolar Depression is just one of the 7 subtypes of Depression, as discussed in a previous article entitled “What is Depression?”
Alas, it can be difficult to tell the difference between Bipolar Depression and Unipolar Depression. You can still use the SIGECAPS mnemonic to determine the presence of a depressive episode, but there are some differences in the presentation of a Bipolar Depression versus a Unipolar Depression:
Bipolar Depression: increased need for sleep (hypersomnia), rejection hypersensitivity (increased sensitivity to rejection), increased appetite, weight gain, and leaden paralysis
Unipolar Depression: multiple early morning awakenings (insomnia), decreased appetite, weight loss, and agitation.
The other main difference between Unipolar and Bipolar Depression is the history of manic episodes in Bipolar Disorder. As with SIGECAPS for a depressive episode, you can use the mnemonic DIGFAST for a manic episode. In addition to expansive, elevated moods, a manic episode needs at least 2 more of the following symptoms:
- Distractibility (inability to focus)
- Insomnia (decreased need for sleep)
- Grandiosity (grandiose delusions)
- Flight of ideas (racing thoughts)
- Activity (hyperactivity)
- Speech (pressured speech)
- Thoughtlessness (reckless and impulsive behaviors)
So in Bipolar Disorder, there is cycling between manic episodes, depressive episodes, and sometimes mixed episodes (mix of manic and depressive symptoms). And when not in any of those episodes, then there is euthymia, or normal moods. Contrast this with Unipolar Depression, where there is only cycling between depressive episodes and euthymia, with no manic episodes.
It’s important to tell the difference between Bipolar Depression and Unipolar Depression, as the treatment plan for each differs dramatically, and the wrong treatment can lead to worsening of the illness and mood episodes.