Previous studies indicate an association between severe psychiatric disorders, such as bipolar disorder, and increased risk of venous thromboembolism. However, to which extent this association is influenced by lithium treatment is currently unknown. In this prospective cohort study, the investigators aim to investigate the effect of bipolar disorder and lithium treatment on coagulation and the counterpart fibrinolysis.

The investigators will analyse differences in coagulation

• using a case-control design where cases are bipolar patients not yet treated with lithium, and controls are healthy volunteers (Swedish ethical review authority Dnr 2023-05799-02, PI Kristoffer Månsson, KI).
• using a prospective cohort design, following the patients over time.

Inclusion Criteria:

• Patients diagnosed with bipolar disorder but not yet treated with lithium, where there is a decision by the patient and the responsible doctor to start lithium treatment.

Exclusion Criteria:

• Inability to give informed consent

Patients diagnosed with bipolar disorder but not yet treated with lithium, where there is a decision by the patient and the responsible doctor to start lithium treatment. Patients are recruited in specialized care.

Not planning to share IPD