How common is bipolar II disorder?

There may be different criteria used to diagnose BPII disorder, so estimates on how common BPII vary.

People can be diagnosed at different ages. Most people experience their first episode in their early 20s, but might not be diagnosed until much later.

Evidence suggests that between 4 in 1000 and 50 in 1000 people will be diagnosed with BPII at some stage in their lifetime. You can see this in the diagram below.

Between 4 in 1000 and 50 in 1000 people will be diagnosed with BPII at some stage in their lifetime.

Between 950 in 1000 and 996 in 1000 people will NOT.