RecruitingPhase 4Drug trialLithium Versus Cariprazine in the Acute Phase Treatment of Bipolar Depression (DUAG9)The goal is to study the effect of lithium compared to cariprazine in patients with depression in a bipolar disease. The main question it aims to answer is: Difference in change between the two groups from baseline to after 8 weeks treatment on Hamilton Ratings Scale for Depression, 6-item version (HDS-6) Participants will be randomized to treatment with either lithium or cariprazin. * Will meet for interview and ratings 4 times during study period. * In two meetings, there will be made blood samples and ECG. At one meeting also a Urine sample. * Will be contacted for telephone interviews at 6 occasions.