ABSTRACT
INTRODUCTION: Core dysfunctions proposed for psychotic disorders include prefrontal cortex (PFC) dopaminergic hypoactivity, executive function (EF) deficits and reduced gray matter in the PFC. The Val variant of COMT Val158Met polymorphism is associated with reduced dopaminergic signaling in the PFC. However, it is unclear how COMT Val158Met modulates PFC gray matter reduction, EF deficits and symptom severity at the time of the first psychotic episode. METHODS: The effect of COMT on both EF performance and prefrontal volume (PFC-VOL) was tested in 158 first episode psychosis (FEP) patients and 141 healthy controls (HC) matched for age (range 9-35 years), sex, ethnicity, handedness and COMT Val158Met distribution. EF and PFC-VOL were compared between FEP and HC groups within each polymorphism status (Met/Met versus Val carriers) to assess whether COMT influenced diagnostic differences. Next, correlations between PFC-VOL and EF performance were computed, as well as between both variables and other clinical characteristics of interest (PANSS scores, PAS infancy and premorbid IQ) in the FEP sample. RESULTS: COMT influenced the diagnostic differences mainly in PFC-VOL, but also in EF performance. FEP-Val carriers showed lower EF scores and reduced PFC-VOL compared to the HC group but also poorer EF performance than FEP Met/Met. Poorer EF performance was associated with smaller PFC-VOL, and both were related to increased severity of negative symptoms, poorer premorbid adjustment, and lower estimated premorbid IQ in FEP patients. CONCLUSIONS: Our findings suggest that COMT Val158Met polymorphism might contribute to PFC-VOL reductions, executive dysfunctions and symptom severity in FEP patients.
Subject(s)
Catechol O-Methyltransferase , Executive Function , Psychotic Disorders , Adolescent , Adult , Catechol O-Methyltransferase/genetics , Child , Dopamine , Executive Function/physiology , Humans , Polymorphism, Genetic , Prefrontal Cortex , Psychotic Disorders/diagnosis , Psychotic Disorders/genetics , Young AdultABSTRACT
Introduction: Core dysfunctions proposed for psychotic disorders include prefrontal cortex (PFC) dopaminergic hypoactivity, executive function (EF) deficits and reduced gray matter in the PFC. The Val variant of COMT Val158Met polymorphism is associated with reduced dopaminergic signaling in the PFC. However, it is unclear how COMT Val158Met modulates PFC gray matter reduction, EF deficits and symptom severity at the time of the first psychotic episode.Methods: The effect of COMT on both EF performance and prefrontal volume (PFC-VOL) was tested in 158 first episode psychosis (FEP) patients and 141 healthy controls (HC) matched for age (range 935 years), sex, ethnicity, handedness and COMT Val158Met distribution. EF and PFC-VOL were compared between FEP and HC groups within each polymorphism status (Met/Met versus Val carriers) to assess whether COMT influenced diagnostic differences. Next, correlations between PFC-VOL and EF performance were computed, as well as between both variables and other clinical characteristics of interest (PANSS scores, PAS infancy and premorbid IQ) in the FEP sample.Results: COMT influenced the diagnostic differences mainly in PFC-VOL, but also in EF performance. FEP-Val carriers showed lower EF scores and reduced PFC-VOL compared to the HC group but also poorer EF performance than FEP Met/Met. Poorer EF performance was associated with smaller PFC-VOL, and both were related to increased severity of negative symptoms, poorer premorbid adjustment, and lower estimated premorbid IQ in FEP patients.Conclusions: Our findings suggest that COMT Val158Met polymorphism might contribute to PFC-VOL reductions, executive dysfunctions and symptom severity in FEP patients. (AU)
Introducción: Algunas de las alteraciones descritas en los trastornos psicóticos incluyen una hipoactividad dopaminérgica en la corteza prefrontal (CPF), déficits en la función ejecutiva (FE) y reducción de la materia gris en la CPF. La variante Val del polimorfismo COMT Val158Met se asocia con una menor disponibilidad dopaminérgica en la CPF. Sin embargo, está aún pendiente de determinar la forma en la que COMT modula la materia gris de la CPF, la FE y la gravedad de los síntomas en el momento del primer episodio psicótico (PEP).Métodos: El efecto de COMT en el rendimiento de la FE y el volumen prefrontal (VOL-CPF) se evaluó en 158 pacientes con PEP y 141 controles sanos (CS) emparejados por edad (9-35 años), sexo, etnia y distribución de COMT. La FE y el VOL-CPF se compararon entre los grupos de PEP y CS, y en función de la variante alélica del polimorfismo (Met/Met versus portadores Val) para evaluar si COMT modula las diferencias diagnósticas. Además, se llevaron a cabo correlaciones entre FE y VOL-CPF, así como entre ambas variables y las puntuaciones en la PANSS, el ajuste premórbido y el CI premórbido.Resultados: COMT moduló las diferencias diagnósticas en VOL-CPF y el rendimiento de FE. Los PEP portadores de la variante Val presentaron menores puntuaciones en FE y reducción del VOL-CPF en comparación con el grupo CS, y menor rendimiento de FE que los PEP Met/Met. Un menor rendimiento en FE se asoció con un menor VOL-CPF, y ambas variables estaban relacionadas con un incremento en la gravedad de síntomas negativos, un peor ajuste premórbido y un menor CI premórbido en pacientes con PEP.Conclusiones: Nuestros hallazgos evidencian que el polimorfismo COMT Val158Met podría contribuir a la reducción del VOL-CPF, la disfunción ejecutiva y la gravedad de los síntomas en los pacientes con PEP. (AU)
