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 ofdepression according 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 weeksprior to 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 witheither lithium 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 psychoticsymptoms as 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.