Voices, Paranoia, Delusions
For reasons not entirely clear, many people, and many doctors among them, seem to believe that hearing voices means a person has schizophrenia. They also believe that paranoia is a symptom of schizophrenia, not bipolar disorder. Severe psychosis — losing contact with reality in some way — equals schizophrenia in many peoples’ minds. This is simply not accurate.
“Psychosis” definitely occurs in bipolar I (by definition, not in Bipolar II). Here is a table that shows just how common this is. It’s a little tricky to figure out what’s being shown here, so please allow me to explain:
Drs. Goodwin and Jamison reviewed many research papers about patients with bipolar disorder. They rounded up 26 that described the kinds of “psychotic features” present in those patients. Note that “grandiose delusions” shows the highest frequency: nearly half of all these patients with bipolar disorder, who had lost contact with reality, had beliefs which were “grandiose”. An example would be “I’m the second coming of Jesus Christ” or “I am physician to the president, I must see him”. The frequency of 47% is an average from all the 26 studies.
The “range” column indicates the lowest and the highest frequency among those studies: in one study, only 35% of the patients had grandiose delusions; in another, 60% did. This is the common conception of bipolar disorder in the manic phase: dramatic,
grandiose, often euphoric. But there is clearly another way to lose contact with reality in bipolar disorder, the table shows.
Notice that 28% had paranoia or paranoid delusions (sometimes a paranoid outlook on the world doesn’t quite develop into delusions as such. Thinking people are out to get you is paranoia, but believing that a hit team from the FBI was in your house last night is a delusion, for example — at least I hope the FBI weren’t in your house last night). But now, notice the “range” figures: in one study, as many as 65% — 2 out of every three patients with bipolar I disorder — had paranoia of one kind or another. This means something very important that many doctors seem not to know: being paranoid, even being paranoid to the point of clear delusions, does not mean a person has paranoid schizophrenia. It is a common feature of bipolar disorder.
The same goes for auditory hallucinations — hearing voices. It’s not as common, only 18% on average, but in one study it was 48%, nearly half of the patients in the study hearing voices. Again, hearing voices does not mean a person has schizophrenia. This too is a relatively common feature of bipolar disorder.
Finally, “Schneiderian First Rank Symptoms” are typically associated with the diagnosis of schizophrenia. They include peculiar delusions, such as a sense that one’s thoughts can be heard by others. The point is that even these symptoms can occur in bipolar disorder, so the “type” of delusion does not clearly establish schizophrenia either — the person might still have bipolar disorder.
How can one tell schizophrenia from bipolar disorder, then? This has been debated since the two were first distinguished from one another, and the debate continues. In my view, one cannot expect to tell this difference from the symptoms a person has at one moment in time. There is far too much overlap of symptoms between the two illnesses — if indeed they are two different illnesses, as opposed to two ends of the same spectrum, as recent genetic data strongly suggest.e.g. Doherty
Only by looking at the pattern of their symptoms over time can one hope to have a solid clue, because there one may find evidence of severe depressive episodes, which are not common features of schizophrenia (depression yes, or something that looks like it somewhat, called “negative symptoms”; but not cyclic depression, with few exceptions). Someday, and hopefully soon, we’ll know enough about what causes “schizophrenia” and “bipolar disorder” to know how they really differ from one another.