TY - JOUR
T1 - Tardive dyskinesia exacerbated after ingestion of phenylalanine by schizophrenic patients
AU - Mosnik, Diane M.
AU - Spring, Bonnie
AU - Rogers, Keith
AU - Baruah, Sankar
N1 - Funding Information:
This research was supported in part by a VA Merit Review grant to Dr. Bonnie Spring, by The National Institute of Mental Health Grants MH31593, MH40856, MHCRC 43271 to Dr. Nancy C. Andreasen at the Mental Health Clinical Research Center, and a NARSAD Young Investigator Award to Dr. Keith Rogers. I would like to thank Dr. Andreasen for generously providing use of her clinical research center, -both the patients and the facilities. In addition, I would like to thank Dr. Lori Moss, from the North Chicago VA, and Mr. Frank Fleming, BSN, from the University of Iowa Mental Health Clinical Research Center (MH-CRC), for their help in subject recruitment and TD reliability ratings. I would also like to thank Dr. Stephan Arndt for statistical advice.
PY - 1997/2
Y1 - 1997/2
N2 - Despite continued research, the influences that promote or exacerbate tardive dyskinesia (TD) symptoms remain incompletely understood. Recent findings (Gardos et al. 1992; Richardson et al. 1989) suggest that ingestion of the dietary constituent, phenylalanine, might exacerbate TD symptoms, but a double-blind, placebo-controlled challenge had not previously been conducted in schizophrenic patients. On two different mornings, in counterbalanced order, 18 male schizophrenic patients with TD were challenged with either 100 mg/kg phenylalanine or placebo. Effects on abnormal involuntary movements, recall memory, and plasma phenylalanine were measured 90 minutes post-challenge. The results supported the hypothesis in that involuntary movements increased to a statistically and clinically meaningful degree after the phenylalanine challenge, but not after placebo. No effects on memory were detected. Significant order effects characterized the plasma findings but not the behavioral data. Results indicate that a dietary constituent, the amino acid phenylalanine, can potentially exacerbate tardive dyskinesia symptoms in schizophrenic patients. The influence of phenylalanine and other ingested substances on clinical symptomatology warrants further investigation.
AB - Despite continued research, the influences that promote or exacerbate tardive dyskinesia (TD) symptoms remain incompletely understood. Recent findings (Gardos et al. 1992; Richardson et al. 1989) suggest that ingestion of the dietary constituent, phenylalanine, might exacerbate TD symptoms, but a double-blind, placebo-controlled challenge had not previously been conducted in schizophrenic patients. On two different mornings, in counterbalanced order, 18 male schizophrenic patients with TD were challenged with either 100 mg/kg phenylalanine or placebo. Effects on abnormal involuntary movements, recall memory, and plasma phenylalanine were measured 90 minutes post-challenge. The results supported the hypothesis in that involuntary movements increased to a statistically and clinically meaningful degree after the phenylalanine challenge, but not after placebo. No effects on memory were detected. Significant order effects characterized the plasma findings but not the behavioral data. Results indicate that a dietary constituent, the amino acid phenylalanine, can potentially exacerbate tardive dyskinesia symptoms in schizophrenic patients. The influence of phenylalanine and other ingested substances on clinical symptomatology warrants further investigation.
KW - amino acids
KW - phenylalanine
KW - schizophrenia
KW - tardive dyskinesia
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U2 - 10.1016/S0893-133X(96)00054-1
DO - 10.1016/S0893-133X(96)00054-1
M3 - Article
C2 - 9015796
AN - SCOPUS:0031081237
SN - 0893-133X
VL - 16
SP - 136
EP - 146
JO - Neuropsychopharmacology
JF - Neuropsychopharmacology
IS - 2
ER -