TCPR: Dr. Shinn, when we see patients with a first episode of psychosis, it can be difficult to know what the diagnosis is and how to proceed with treatment. What’s the approach of your program at McLean Hospital?
Dr. Shinn: We start with a good diagnostic assessment. We elicit a patient’s history, talk to family members (patient permitting), and review prior medical records. It’s important to realize that psychosis can result from many different non-psychiatric conditions—for example, substance use, electrolyte imbalances, thyroid abnormalities, systemic infections, nutritional deficiencies, brain tumors, and seizures, among others. By the time we see them, patients have usually already had a basic medical evaluation in an inpatient hospital or emergency room, and most non-psychiatric medical causes have been ruled out. If an adequate first-episode workup has not been done, we order labs and studies, including a toxicology screen, complete blood count, comprehensive metabolic panel, thyroid stimulating hormone, folic acid, vitamin B12, RPR, ceruloplasmin (to rule out Wilson’s disease), and possibly serologies for diseases like Lyme and HIV. We may also order a brain MRI and/or EEG if there is high suspicion of a structural brain lesion or if there are seizures in the clinical history.
TCPR: After organic causes of psychosis have been ruled out, how do you think about the diagnosis?
Dr. Shinn: I think of psychotic disorders as fitting into two broad categories: primary or secondary. Primary psychotic disorders include schizophrenia, schizoaffective disorder, and schizophreniform disorder. In primary psychotic disorders, psychotic symptoms are the principal problem and are more or less present throughout the course of illness. By contrast, psychosis can be secondary, occurring in the context of other conditions. In addition to organic causes, which I already mentioned, a number of psychiatric conditions can present with psychosis. Mood disorders like bipolar disorder or major depressive disorder, also known as “affective psychoses,” are among the most common of these. In affective psychosis, psychotic symptoms are present only when a person is manic or depressed. There are no psychotic symptoms inter-episode, ie, in the periods between mood episodes.
TCPR: But then there’s that gray zone of “schizoaffective disorder.”
Dr. Shinn: Right. There can be significant overlap in symptoms. Evidence suggests that these disorders are not biologically discrete, but rather lie on a continuum. A patient with schizoaffective disorder will have episodes of psychosis with depression and/or mania, but will be more like a patient with schizophrenia in that the psychotic symptoms are persistent, continuing even after the symptoms of depression or mania have resolved.
TCPR: Given that schizophrenia, schizoaffective disorder, and psychotic mood disorders share so many symptoms, how can you distinguish among them?
Dr. Shinn: Schizoaffective disorder and psychotic bipolar disorder can be particularly hard to distinguish when someone presents acutely with both prominent mood and psychotic symptoms. In such instances, we rely on information about the person’s longitudinal course. When there is little past psychiatric history to guide us, as is typically the case with new-onset psychosis, we have to follow the patient’s course over time to be more certain about the diagnosis.
TCPR: That makes sense. Can you give us a specific example?
Dr. Shinn: Yes. We saw a young man who experienced his first psychotic episode at the start of his senior year in college. He was easily distracted, heard voices, and had ideas of reference, such as thinking that his professor was lecturing specifically about him. His roommates, teachers, and coaches became concerned, and the patient was forced to leave school. He went to live at his parents’ house, where he could not sleep, had racing thoughts, and ended up smashing some cars with a baseball bat thinking that Martians were invading Earth and that he had to lead a revolution against them. He was hospitalized at a community psychiatric hospital, and diagnosed with unspecified psychosis (formerly termed “psychosis not otherwise specified”). After hospitalization, he became severely depressed; he was prescribed antidepressants at his local clinic, but did not improve. That is when he was referred to our program. After seeing the patient and going through his medical records, we diagnosed him with bipolar disorder with psychotic features and started him on lithium, and he’s done quite well.
TCPR: Under what circumstances might this patient have been diagnosed with schizoaffective disorder?
Dr. Shinn: If there were periods when manic and depressive symptoms were absent, but he continued to have psychotic symptoms.
TCPR: You recently reported on a series of patients who have come to your clinic with first-episode psychosis. It would be interesting for us to get a sense of the diagnostic breakdown of these patients.
Dr. Shinn: Yes, we reported on the patients we treated during the first 2.5 years of our program’s existence. Among the 89 patients who presented to our clinic with first-episode psychosis, 33% had a primary psychotic disorder, 44% had affective psychosis, and 21% had psychosis NOS at the time of referral.