Part 2: How do you tell bipolar disorder, schizophrenia apart?

Mental Health Expert Dr. Charles Raison Psychiatrist,
Emory University Medical School

Expert answer

Dear Tony,

This week we pick up where we left off last week. If you didn't see last week's entry regarding this question, click here.

When I was a psychiatry resident at UCLA I had an ongoing friendly disagreement with a friend of mine named Matthew State, who was one of the best residents I ever knew and who has gone on to become a famous psychiatric genetics researcher. Matt maintained steadfastly in those years that because psychiatric disorders actually existed as distinct entities, every patient could be described fully by one or more diagnoses. If you couldn't do this you hadn't tried hard enough.

In contrast, I maintained then, and still maintain, that psychiatric diagnoses are like Platonic ideals, they are "perfect types" that patients more or less approximate. Because of this some patients have histories that walked right out of the DSM-IV diagnostic manual, but others have stories that fall between the diagnostic cracks and that, therefore, will never fit a diagnosis very well no matter how hard you try.

You can see why I'm telling this story. While modern psychiatry was built to no small degree upon the belief that schizophrenia and bipolar disorder were separate psychotic illnesses, I think data increasingly suggest they are more similar than different. You can see this any way you look at it.

More and more studies suggest that they share genetic risk factors. That, in fact, there may be some genes that predispose one to psychosis and other genes that predispose one to mood disorders. If you just get the psychotic genes you look schizophrenic. To the degree you get both types of risk genes you look more bipolar. Although as I mentioned last week, lithium works for bipolar disorder but not for schizophrenia, in the last decade a small army of medications has been introduced onto the market that work well for both conditions, strongly suggesting a shared neurobiology.

Finally, long term follow-up studies have shown that schizophrenia doesn't always lead to an unremitting downward spiral, and, unfortunately, bipolar disorder is not a condition characterized by no long-term damage. In fact, it is increasingly clear that the deterioration in functioning over time that was once thought to be a hallmark for schizophrenia is also very common in people with bipolar disorder.

So these comments answer your first and third question, leaving the question of how to tell a psychotic mania apart from a schizophrenic psychotic episode. Every psychiatrist in the world believes he or she can do this, but the best data on the issue suggest this isn't true. In fact, any symptom present during a psychotic episode can occur in people who, over time, look more schizophrenic or who look more bipolar. Having said this, however, because I am a psychiatrist I, like everyone else, think I can make an educated guess about whether someone is manic.

Here are a few clinical "pearls" for identifying a manic psychosis. First, manias tend to come on more quickly than schizophrenic episodes. They are often preceded and accompanied by remarkable reductions in sleep. Classic manic episodes are characterized by profound mood changes. These are easiest to recognize when the mood is euphoric, but rage is just as common, and more dangerous. If you see a psychotic patient who is moving and speaking a million miles an hour, that doesn't prove he is manic, but it is a pretty strong clue. Finally, although data show you can't separate out manic from schizophrenic episodes by the quality of the psychotic delusions, I have always been impressed by the fact that at the core of manic delusions is a sense that everything in the universe is connected in strange and meaningful ways. Again this isn't specific for mania, but if this type of thinking is present along with other symptoms I've described, it is a tip that someone is having a manic episode.

So let me end on one final note of confusion/uncertainty. Long-term studies of patients who are schizophrenic suggest that a high percentage of them will have at least one manic episode in their lives! So what is the take-home message? Both schizophrenia and bipolar disorder are serious and often devastating conditions that have the best outcomes when treated early and aggressively. You don't want to leave someone in any type of psychotic state for one moment longer than you have to.