Diagnostic shift common after FEP
MedWire News: Around a fifth of patients who have suffered a first episode of psychosis (FEP) have their diagnosis changed at the time of recurrence, research shows.
"With its characteristic fluctuating symptomatology and unclear mood symptoms, FEP may be more vulnerable to diagnostic change over time compared to later stages of psychosis," explain Kyung Sue Hong (Sungkyunkwan University School of Medicine, Seoul, Republic of Korea) and team
They add: "Accurate diagnosis at the first episode is important for planning medical and psychosocial treatments. In addition, diagnostic change during follow-up could influence doctor-patient rapport and patient's compliance to the treatment."
To investigate the prevalence of diagnostic change after an FEP, the team studied data on 150 patients who had been admitted to the Samsung Medical Center in Seoul with a first psychotic episode, and who were later readmitted with a second psychotic episode between 1994 and 2009. The mean interval between the first and second psychotic episode was 27.1 months.
The most common diagnosis at the time of the first episode was schizophrenia (n=92) followed by bipolar disorder (n=38).
The researchers found that 20.7% (n=31) of patients had their diagnoses changed at the time of the second psychotic episode.
Overall, 33.9% of patients with a diagnosis of affective psychosis (n=53) at the time of recurrence had initially been diagnosed with nonaffective psychosis.
The most common diagnostic shift was to bipolar disorder, which accounted for more than half of all diagnostic changes.
Schizophrenia exhibited the highest prospective and retrospective diagnostic stability.
Predictive factors for a diagnostic shift from nonaffective psychosis to bipolar disorder included female gender, short duration of untreated psychosis, a high level of premorbid functioning, and symptoms including lability, mood elation, hyperactivity, and delusions of a religious or grandiose nature.
"More than one-fifth of the patients who presented with FEP were given a different diagnosis upon recurrence," the researchers summarize. "The most common change was to a diagnosis of bipolar disorder from original diagnoses of schizophrenia, schizophreniform disorder, and brief psychotic disorders."
They conclude: "The present study suggests that the clinical features of FEP evolve over the disease course and that a rigid adherence to DSM-IV requirements may lead to an under diagnosis of initial bipolar disorder."
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By Mark Cowen