Artifactual Rediagnosis of Psychotic Depression as Schizophrenia
To the Editor: Psychopathology is changed by antipsychotic-type medications, but Ruggero et al1 did not account for effects of exposure to medication on diagnosis. Diagnosis of functional disorders per DSM requires absence of medical effects—including effects from medications—that can cause or suppress disorder criteria contents. Antipsychotic-type drugs tend to suppress symptoms, including those of depression and psychosis. As a separate matter, when given chronically these drugs can cause tardive psychosis, the symptoms of which resemble schizophrenia.2 Measurable deteriorative brain changes provide further evidence of neuropsychiatric toxicity from antipsychotic drugs.3,4
Ruggero et al1 report that diagnoses of some patients changed from psychotic depression to schizophrenia spectrum disorders. They did not mention that such a change can result at least in part from exposure to antipsychotic drugs. If an antipsychotic drug were to suppress mood symptoms but only mitigate psychosis in a psychotic mood disorder, the apparent result on DSM diagnosis could be a change to a schizophrenia spectrum disorder. Induction of tardive psychosis can separately bring this same change in diagnosis. Attributing an apparent change in diagnosis to antipsychotic-type drugs may increase the clinical importance of the observations of Ruggero et al.1
Others have similarly reported that patients maintained on treatment with antipsychotic drugs for conditions aside from schizophrenia are eventually rediagnosed with schizophrenia.5 So it seems time to raise the bar for quality in clinical studies by requiring that psychiatric diagnosis consider both reversible and permanent effects of antipsychotic drugs and other psychotropics.
References
1. Ruggero CJ, Kotov R, Carlson GA, et al. Diagnostic consistency of major depression with psychosis across 10 years. J Clin Psychiatry. 2011;72(9):1207-1213. PubMed doi:10.4088/JCP.10m06774
2. Swartz CM. Tardive psychopathology. Neuropsychobiology. 1995;32(3):115-119. PubMed doi:10.1159/000119222
3. Dorph-Petersen KA, Pierri JN, Perel JM, et al. The influence of chronic exposure to antipsychotic medications on brain size before and after tissue fixation: a comparison of haloperidol and olanzapine in macaque monkeys. Neuropsychopharmacology. 2005;30(9):1649-1661. PubMed doi:10.1038/sj.npp.1300710
4. Ho BC, Andreasen NC, Ziebell S, et al. Long-term antipsychotic treatment and brain volumes: a longitudinal study of first-episode schizophrenia. Arch Gen Psychiatry. 2011;68(2):128-137. PubMed doi:10.1001/archgenpsychiatry.2010.199
5. Whitty P, Clarke M, McTigue O, et al. Diagnostic stability four years after a first episode of psychosis. Psychiatr Serv. 2005;56(9):1084-1088. PubMed doi:10.1176/appi.ps.56.9.1084
Author affiliations: Department of Psychiatry, Oregon Health and Science University, Portland; and Department of Psychiatry, Southern Illinois University School of Medicine, Springfield. Potential conflicts of interest: Dr Swartz is a stock shareholder in Abbott Laboratories, IntelGenx Technologies Corp, and Vanguard Health Care Fund. Funding/support: None reported.
doi:10.4088/JCP.11lr07621
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