There is a close relationship between bipolar disorder, schizophrenia and schizoaffective disorder. These three conditions share genetic roots as well as symptoms, and many of the medications prescribed for one are also prescribed for the others. Still, current definitions of bipolar and schizoaffective disorders, along with schizophrenia, contain clear differences.
The hallmark symptom of bipolar disorder is mood swings. A major depressive episode of bipolar is about the same as one of major depressive disorder, but there are also episodes of mania or hypomania plus mixed episodes that have features of both depression and mania/hypomania. Where bipolar overlaps with schizophrenia and schizoaffective disorder is that a manic episode of Bipolar I can include the psychotic symptoms hallucinations and delusions.
There are symptoms of schizophrenia that don't appear in bipolar disorder:
- Disorganized speech (where speech is difficult to follow or bizarre)
- Grossly abnormal physical behavior (such as catatonia) related to mental processes (called psychomotor behavior), and
- "Negative" symptoms, including such things as reduced expressiveness in facial expressions as gestures and lack of self-initiated behavior.
Schizophrenia with major mood disorder can be diagnosed if depressive and/or manic symptoms occur at the same time as pure schizophrenia symptoms.
This is a trickier diagnosis. First of all, there must be symptoms of schizophrenia and either a major depressive or manic episode at the same time for a period of time. Secondly, the patient must have delusions and/or hallucinations for a period of at least two weeks when not having a manic or depressive episode. Finally, major mood episodes must be present at least 50% of the time.
The key here is that there have to be psychotic symptoms by themselves that aren't part of what could be called a bipolar episode.
Diagnostic Oddities in Bipolar, Schizoaffective and Schizophrenia
Again and again I see news stories where a person is described as having bipolar disorder and schizophrenia. Since schizophrenia with major mood disorder exists, since schizoaffective disorder exists, one would think there should be very few - if any - circumstances where both bipolar disorder and schizophrenia are diagnosed in a single person.
And yet - in his article Bipolar Disorder and Schizophrenia - More Closely Related than You Might Think, John McManamy takes a look at the history of the two illnesses, their similarities, and the interesting possibility that the two can manifest at different times in a person's life.
Research is always pushing the boundaries of what we know about mental illnesses. The intertwinings of these bipolar disorder, schizophrenia and schizoaffective disorder will surely be illuminated further as time passes.