Medication for bipolar versus unipolar depression

How are bipolar and unipolar depression different?

Bipolar disorders are a group of disorders characterised by episodes of depression and mania or hypomania. Bipolar disorders described in the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, version 5) include bipolar I disorder involving severe depression and mania, bipolar II disorder involving depression and hypomania (less severe mania), and cyclothymic disorder involving many mood swings, with hypomania and depressive symptoms occurring often and fairly constantly.

Major depressive disorder characterised in the DSM-5 involves five (or more) of the following symptoms to be present and represent a change from previous functioning. At least one of the symptoms must be either depressed mood or loss of interest or pleasure, with no history of mania.
• Depressed mood most of the day, nearly every day
• Diminished interest/pleasure in all, or almost all, activities most of the day, nearly every day
• A change of more than 5% of body weight in a month or decrease/increase in appetite
• Insomnia or hypersomnia
• Fatigue or loss of energy
• Psychomotor agitation or retardation that is observable by others
• Feelings of worthlessness or excessive or inappropriate guilt
• Diminished ability to think or concentrate, or indecisiveness
• Recurrent thoughts of death or a suicide attempt or plan

What is the evidence for differences in treatment response between bipolar and unipolar depression?

Moderate to low quality evidence suggests no differences in depression severity between people with bipolar or unipolar depression after treatment with antidepressants. There are small, but clinically significant effects of improved depression symptoms with any antidepressant for major depressive disorder. For bipolar disorder, the antidepressant paroxetine, antipsychotics aripiprazole, lurasidone, olanzapine, quetiapine, and ziprazidone, and mood stabilisers lithium, lamotrigine, and divalproex also have small, but clinically significant effects for improving depression.

November 2021

Image: ©freshidea –

Last updated at: 5:31 pm, 15th February 2022
To view documentation related to this topic download the files below
Fact Sheet Technical Commentary
Tags:  Depression

NeuRA Libraries

Title Colour Legend:
Green - Topic summary is available.
Orange - Topic summary is being compiled.
Red - Topic summary has no current systematic review available.