Bipolar disorder and ADHD can make it difficult to get things done and have meaningful relationships. And yet the two mental illnesses are very different from one another. See the key differences in this simple infographic.
Both of these illnesses are serious and require ongoing psychiatric treatment. Out of control, either than severely disrupt a person's life and relationships. Perhaps Schizoaffective Disorder may be a little more complicated, because the person still has psychotic symptoms even when no active mood problem is expressing itself. So, the medications needed may be more.