I am not entirely sure what you mean by a cut off...but schizophrenia is a 'thought' disorder and bipolar/depression are mood disorders. A person having symptoms of both thought and mood disorders could possibly have schizoaffective disorder-bipolar type. There are some articles on all of these different issues if you look at the 'conditions' tab at the top of this website.
The value in having a label is in getting the correct treatment. However, a mental illness label does not affect the value of an individual. I am a person with bipolar disorder...I am not 'bipolar'. No more than I would say I am excema, or I am arthritis. I am a person with excema and arthritis.