The relationship between COMT, proline, and negative symptoms in clinical high risk and recent psychosis onset.

Individuals at clinical high-risk (CHR) of developing psychosis, as well as patients with recent psychosis onset (RO), experience significant negative symptoms that detrimentally impact daily-life functioning and are associated with poor outcomes, even in those who do not convert to psychosis. Targeting negative symptoms may thus hold promise for the treatment of CHR and RO patients. Building from previous findings we examined whether the catechol-O-methyltransferase (COMT) ValMet functional polymorphism and fasting peripheral proline concentration predicts the severity of negative symptoms experienced by adolescents and young adults at CHR or those with RO.

Analysis of the impact of antidepressants and other medications on COVID-19 infection risk in a chronic psychiatric in-patient cohort.

Background: During the first wave of the coronavirus disease 2019 (COVID-19) pandemic, patients with confirmed cases in New York State accounted for roughly 25% of total US cases, with psychiatric hospital in-patients at particularly high risk for COVID-19 infection.

Aims: The beneficial effects of mental health medications, such as selective serotonin reuptake inhibitors (SSRIs), on the severity of COVID-19 disease outcomes have been documented. Protective effects against infection have also been suggested for these medications.

Regulation of cortical and peripheral GCH1 expression and biopterin levels in schizophrenia-spectrum disorders.

Tetrahydrobiopterin (BH) is an essential cofactor for dopamine, serotonin and nitric oxide synthesis. Deficits of plasma total biopterin (a measure of BH) have been described in schizophrenia and schizoaffective disorder. GCH1 encodes the first and rate-limiting enzyme in BH synthesis.

Vitamin D insufficiency and schizophrenia risk: evaluation of hyperprolinemia as a mediator of association.

25-Hydroxyvitamin D (25(OH)D) deficits have been associated with schizophrenia susceptibility and supplementation has been recommended for those at-risk. Although the mechanism by which a deficit confers risk is unknown, vitamin D is a potent transcriptional modulator and can regulate proline dehydrogenase (PRODH) expression. PRODH maps to chromosome 22q11, a region conferring the highest known genetic risk of schizophrenia, and encodes proline oxidase, which catalyzes proline catabolism.

Utilization of never-medicated bipolar disorder patients towards development and validation of a peripheral biomarker profile.

There are currently no biological tests that differentiate patients with bipolar disorder (BPD) from healthy controls. While there is evidence that peripheral gene expression differences between patients and controls can be utilized as biomarkers for psychiatric illness, it is unclear whether current use or residual effects of antipsychotic and mood stabilizer medication drives much of the differential transcription. We therefore tested whether expression changes in first-episode, never-medicated BPD patients, can contribute to a biological classifier that is less influenced by medication and could potentially form a practicable biomarker assay for BPD.

Evidence for association of hyperprolinemia with schizophrenia and a measure of clinical outcome.

There are multiple genetic links between schizophrenia and a deficit of proline dehydrogenase (PRODH) enzyme activity. However, reports testing for an association of schizophrenia with the resulting proline elevation have been conflicting. The objectives of this study were to investigate whether hyperprolinemia is associated with schizophrenia, and to measure the relationship between plasma proline, and clinical features and symptoms of schizophrenia.

Analysis of plasma biopterin levels in psychiatric disorders suggests a common BH4 deficit in schizophrenia and schizoaffective disorder.

Tetrahydrobiopterin (BH4) is an essential cofactor for amine neurotransmitter synthesis. BH4 also stimulates and modulates the glutamatergic system, and regulates the synthesis of nitric oxide by nitric oxide synthases. A connection between BH4 deficiencies and psychiatric disorders has been previously reported; major depression and obsessive-compulsive disorder have been found in subjects with a BH4 deficiency disorder and more recently we have observed a robust plasma deficit of biopterin (a measure of BH4), in a large group of schizophrenic patients compared to control subjects.

Investigation of the phenylalanine hydroxylase gene and tardive dyskinesia.

Phenylketonuria (PKU), an inborn error of phenylalanine metabolism, has been shown to be a risk factor for tardive dyskinesia (TD). In male psychiatric patients there was a significant relationship between TD and measures of plasma phenylalanine following ingestion of a standardized phenylalanine dose that was indicative of higher brain availability of phenylalanine in patients with TD. In addition, a medical food formulation consisting of branched chain amino acids, which compete with phenylalanine for transport across the blood-brain barrier, has been demonstrated to be an efficacious treatment for TD.

Evidence for a tetrahydrobiopterin deficit in schizophrenia.

Tetrahydrobiopterin (BH(4)) is a vital cofactor maintaining availability of the amine neurotransmitters [dopamine (DA), noradrenaline (NA), and serotonin (5-HT)], regulating the synthesis of nitric oxide (NO) by nitric oxide synthase (NOS), and stimulating and modulating the glutamatergic system (directly and indirectly). These BH(4) properties and their potential relevance to schizophrenia led us to investigate the hypothesis of a study group (healthy controls, n=37; schizophrenics, n=154) effect on fasting plasma total biopterin levels (a measure of BH(4)). Study analysis showed a highly significant deficit of total biopterins for the schizophrenic sample after partialling out the effects of potential confounds of gender, age, ethnicity, neuroleptic use history and dose of current use, 24-hour dietary phenylalanine/protein ratio (a dietary variable relevant to BH(4) synthesis), and plasma phenylalanine (which stimulates BH(4) synthesis).

Branched chain amino acid treatment of tardive dyskinesia in children and adolescents.

Background: A series of studies had demonstrated that deficient clearance of the large neutral amino acid phenylalanine was associated with tardive dyskinesia (TD), that the administration of the branched chain amino acids (BCAA) significantly decreased TD symptoms over placebo, and that the observed TD symptom reduction was significantly correlated with a diminished availability of phenylalanine to the brain of adult men with psychosis. As part of an initiative by the National Institute of Mental Health to expand the testing of treatments that were successful in adults to children and adolescents, the present pilot study was undertaken to test whether the BCAA would also reduce TD symptoms in children and adolescents. A 2-week trial of the BCAA was thus conducted in 6 children and adolescents (age range, 10.

Efficacy of the branched-chain amino acids in the treatment of tardive dyskinesia in men.

Objective: The efficacy of the branched-chain amino acids in the treatment of tardive dyskinesia in men with psychiatric disorders was tested.

Method: Public-sector psychiatric patients with long histories of antipsychotic treatment and presumably long-standing tardive dyskinesia were randomly assigned to receive branched-chain amino acids or placebo. Treatment frequency was three times a day, 7 days a week for 3 weeks.

Phenylalanine hydroxylase gene in psychiatric patients: screening and functional assay of mutations.

Background: Reports relating phenylalanine kinetics and metabolism to psychiatric disorders led us to undertake the comprehensive screening of the phenylalanine hydroxylase (PAH) coding region and functional testing of discovered mutations in a sample of psychiatric patients and healthy control subjects.

Methods: Genomic DNA from psychiatric patients and control subjects was assayed for sequence variants in all PAH coding regions and splice junctions. In vivo functional analysis of mutations was conducted by assessing the kinetics and conversion to tyrosine of a standardized phenylalanine dose and by measuring fasting pterin levels.