Lithium Versus Cariprazine in the Acute Phase Treatment of Bipolar Depression (DUAG9)

Inclusion Criteria:

• A diagnosis of bipolar disorder, type 1 or type 2, and a current episode of depressionaccording to DSM-5
• Severity of depression: A score of at least 21 on the self-reported Major DepressionInventory (MDI).
• No start or dose increase of psychotropic medication (except for benzodiazepines andbenzodiazepine-like drugs (zopiclone, zolpidem, and melatonin)) in the two weeks priorto inclusion.
• No new start of formalized psychotherapy sessions, excluding psychoeducation, duringthe 4 weeks prior to inclusion.
• Age criteria: Subjects must be at least 18 years old and below 65 at the time ofrandomization.
• The duration of the current depressive episode must be between 4 and 52 weeks asjudged by the investigator at the time of randomization.
• Clinical uncertainty regarding which of the alternatives, cariprazine and lithium,would be the better choice in the specific case.
• Female participants should be sterile or non-fertile or, in case of being fertile,they must have a negative pregnancy test AND use safe anticonception.
• Signed document of informed consent.

Exclusion Criteria:

• Prior or ongoing acute treatment of a depressive episode lasting > 14 days with eitherlithium or cariprazine as judged by the investigator.
• ECT within the current depressive episode.
• A score of MAS > 6.
• A diagnosis of dementia.
• High risk of non-adherence at the investigator's discretion.
• Not understanding the Danish language as judged by the investigator
• Psychiatric coercion in the form of forced admission or detainment OR sentence toforensic psychiatric care.
• Presence of clinically relevant delusions, hallucinations or other psychotic symptomsas judged by the investigator.
• Suicidality according to C-SSRS with a positive response to question 4 or 5 or uponinvestigator's discretion.
• Medical conditions like cancer, kidney failure, epilepsy, deep brain stimulationdevice, or other medical conditions interfering with study the outcome and safety asjudged by investigator's discretion.
• Current harmful use or dependency of alcohol or drugs according to DSM-5.
• Known allergy to any of the substances in the study medication.