The impact of a history of psychotic symptoms on cognitive function in euthymic bipolar patients : a comparison with schizophrenic patients and healthy controls

Abstract

Introducao: Cerca de dois tercos dos pacientes com Transtorno Bipolar (TB) apresentam sintomas psicoticos ao longo da vida. Objetivo: Comparar o desempenho neurocognitivo de quatro grupos: pacientes com TB, com e sem historico de sintomas psicoticos (HPS+ ou HPS-, respectivamente); pacientes esquizofrenicos; e grupo controle (GC) com individuos saudaveis. Metodos: Estudo transversal no qual 35 pacientes com esquizofrenia (EZ), 79 pacientes com TB na fase eutimica (44 HPS+ e 35 HPS-) e 50 GC foram submetidos a extensa avaliacao neuropsicologica. Resultados: Observou-se pior funcionamento neurocognitivo em pacientes com TB e com EZ quando comparados ao GC. Os dois grupos de pacientes TB nao diferiram em dados demograficos, clinicos ou variaveis neurocognitivas. Entretanto o grupo HPS+ teve mais sintomas negativos mensurados pela Positive and Negative Syndrome Scale (PANSS) e apresentou uma tendencia a pior performance nas funcoes executivas comparativamente aos pacientes HPS-. Alem disso ambos os grupos de pacientes TB tiveram melhor desempenho em todos testes neurocognitivos quando comparados aos pacientes com EZ. Conclusoes: A disfuncao neurocognitiva e mais marcada nos pacientes com EZ do que com TB, apesar de ser qualitativamente similar. Um historico de sintomas psicoticos no TB nao associou esta amostra de pacientes eutimicos a um maior prejuizo neurocognitivo. Assim sendo, o TB com sintomas psicoticos parece nao possuir um fenotipo neurocognitivo diferenciado.

Background: About two-thirds of patients with bipolar disorder (BD) have a lifetime history of at least one psychotic symptom. Objective: To compare the neurocognitive performance of four groups: BD patients with and without a history of psychotic symptoms (BD HPS+ and BD HPS-, respectively); patients with schizophrenia (SZ); and healthy control (HC) subjects. Method: In this cross-sectional study, 35 stabilized patients with SZ, 79 euthymic (44 HPS+ and 35 HPS-) patients with BD, and 50 HC were administered a comprehensive battery of neuropsychological tests. Results: There was worse neurocognitive functioning in both BD and SZ patients compared to HC. Overall, data from both groups of BD patients did not differ on sociodemographic, clinical, or neurocognitive variables. However, BD HPS+ patients had significantly more negative symptoms, as measured by the Positive and Negative Syndrome Scale (PANSS), and showed a trend toward worse performance on executive functions compared to BD HPS- patients. Moreover, both BD groups had better performance on all neurocognitive tests compared to SZ group. Conclusions: Neurocognitive dysfunction may be more marked in SZ than in BD, yet qualitatively similar. A history of past psychotic symptoms in BD was not associated with more severe cognitive impairment during euthymia. Therefore, BD with psychotic symptoms does not appear to be a distinct neurocognitive phenotype.