An examination of associations between the inability to taste phenylthiocarbamide (PTC) and clinical characteristics and trait markers in first-episode, nonaffective psychotic disorders

• Type of Material: Article
• Authors: Michael T. Compton, George Washington University; Dawn Flosnick Ionescu, George Washington University; Beth Broussard, George Washington University; Sarah L. Cristofaro, Emory University; Stephanie Johnson, Emory University; Patrick J. Haggard, Emory University; Amy A. Potts, Emory University; Claire Ramsay Wan, Emory University; Elaine Walker, Emory University
• Language: English
• Date: 2013-08-30
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 Elsevier Ireland Ltd.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.psychres.2013.03.028
• Title of Journal or Parent Work: Psychiatry Research
• ISSN: 0165-1781
• Volume: 209
• Issue: 1
• Start Page: 27
• End Page: 31
• Grant/Funding Information: Funding for this project was made possible through a grant from the National Institute of Mental Health, R01 MH081011.
• Keywords: Phenylthiocarbamide (PTC); Psychosis; PERCEPTION; Endophenotype; MINI-MENTAL-STATE; SCHIZOPHRENIA; GENETICS; LOCUS; Schizophrenia; Science & Technology; FAMILY; RELIABILITY; First-episode psychosis; Life Sciences & Biomedicine; SENSITIVITY; PERFORMANCE; ENDOPHENOTYPES; Psychiatry
• Research Categories: Psychology, Clinical; Health Sciences, Mental Health

Abstract

Research findings are mixed as to whether or not the inability to taste phenylthiocarbamide (PTC) might represent an endophenotypic trait marker for schizophrenia. We hypothesized associations between PTC-tasting status and select clinical characteristics and trait markers in patients with psychotic disorders that, if present, would provide support for the inability to taste PTC as a trait marker. In a first-episode psychosis sample (n=93), we measured PTC tasting, family history of psychosis, age at onset of prodrome and psychosis, severity of positive and negative symptoms, global impairment in functioning, neurological soft signs, and four neurocognitive domains (verbal learning/memory, visual learning/memory, verbal working memory, and spatial working memory). Associations between PTC-non-tasting and clinical/neurocognitive variables were examined with χ2 tests and independent samples t tests. Among participants, 67.7% tasted PTC in comparison to a strip of control paper, and 25.8% were non-tasters. Tasters and non-tasters did not show statistically significant differences with respect to family history, age at onset, severity of symptoms, neurological soft signs, or the four neurocognitive domains. In conjunction with other findings, it is unlikely that PTC-non-tasting is a trait marker of schizophrenia, though a conclusive study is warranted.