Diagnostic and treatment implications of psychosis secondary to treatable metabolic disorders in adults: a systematic review.
OBJECTIVE
It is important for psychiatrists to be aware of certain inborn errors of metabolism (IEMs) as these rare disorders can present as psychosis, and because definitive treatments may be available for treating the underlying metabolic cause. A systematic review was conducted to examine IEMs that often present with schizophrenia-like symptoms.


METHODS
Published literature on MEDLINE was assessed regarding diseases of homocysteine metabolism (DHM; cystathionine beta-synthase deficiency [CbS-D] and homocysteinemia due to methyltetrahydrofolate reductase deficiency [MTHFR-D]), urea cycle disorders (UCD), acute porphyria (POR), Wilson disease (WD), cerebrotendinous-xanthomatosis (CTX) and Niemann-Pick disease type C (NP-C).


METHODS
Case reports, case series or reviews with original data regarding psychiatric manifestations and cognitive impairment published between January 1967 and June 2012 were included based on a standardized four-step selection process.


METHODS
All selected articles were evaluated for descriptions of psychiatric signs (type, severity, natural history and treatment) in addition to key disease features.


RESULTS
A total of 611 records were identified. Information from CbS-D (n = 2), MTHFR-D (n = 3), UCD (n = 8), POR (n = 12), WD (n = 11), CTX (n = 14) and NP-C publications (n = 9) were evaluated. Six non-systematic literature review publications were also included. In general, published reports did not provide explicit descriptions of psychiatric symptoms. The literature search findings are presented with a didactic perspective, showing key features for each disease and psychiatric signs that should trigger psychiatrists to suspect that psychotic symptoms may be secondary to an IEM.


CONCLUSIONS
IEMs with a psychiatric presentation and a lack of, or sub-clinical, neurological signs are rare, but should be considered in patients with atypical psychiatric symptoms.
Department of Child and Adolescent Psychiatry, Centre Hospitalier Universitaire de Nantes, Hôpital Mère-Enfant, 7 quai Moncousu, 44 000 Nantes, France. olivier.bonnot@chu-nantes.fr.
Olivier
O
Bonnot
Hans Hermann
HH
Klünemann
Frederic
F
Sedel
Sylvie
S
Tordjman
David
D
Cohen
Mark
M
Walterfang
D006801:Humans; D008659:Metabolic Diseases / Q000150:complications*; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000209:etiology / Q000628:therapy*