Cannabis use, cognition and brain structure in first-episode psychosis.

Cannabis use is highly prevalent worldwide and it is associated with psychosis, but its effects on brain structure and cognition are still controversial. The aim of this paper is to investigate cognitive functioning and brain structure in patients with their first episode of psychosis who used Cannabis. We examined gray matter and lateral ventricle volumes in 28 patients with first-episode psychosis and a history of Cannabis use, 78 patients without a history of Cannabis use and 80 healthy controls who had not used Cannabis. Cognition was assessed using forward and backwards digit span tests, from the Wechsler Memory Scale-Third Edition (WMS-III) and the Controlled Oral Word Association Test (COWAT). Patients with a history of Cannabis use had less brain abnormalities, characterized by gray matter and lateral ventricle volume preservation, as well as less attentional and executive impairments compared to patients without a history of Cannabis use. Cannabis-using patients who develop psychosis have less neurodevelopmental impairment and better cognitive reserve than other psychotic patients; perhaps reflecting different etiological processes.

Disfunções cognitivas em sujeitos portadores de esquizofrenia no Brasil: amplitude, gravidade e relação com a demora no acesso ao tratamento médico / Cognitve dysfunctions in subjects with schizophrenia in Brazil: extent, severity and association with delay in the access to medical treatment

Introdução: As psicoses funcionais são transtornos psiquiátricos cuja principal característica é a perda da capacidade de julgar apropriadamente a realidade em decorrência de alterações na esfera do pensamento, percepção, emoção, movimento e comportamento. A esquizofrenia é o principal destes quadros, com curso crônico e/ou deteriorativo nas esferas social e ocupacional, gerando enormes custos pessoais e financeiros para os pacientes e cuidadores em todo o mundo. Estudos prévios têm mostrado a existência de prejuízos cognitivos em pacientes com transtornos psicóticos já no início da doença, sendo estes mais graves na esquizofrenia. Há evidências de que estes prejuízos são tanto inerentes aos próprios processos da doença quanto secundários ao tratamento. O presente estudo procurou caracterizar o perfil cognitivo de pacientes com psicoses de início recente (n=56), até 3 anos após o primeiro contato com serviços de saúde mental, sendo 34 com esquizofrenia e 22 com psicoses afetivas. Tais grupos de pacientes tiveram seu desempenho cognitivo comparado com o de um grupo controles saudável (n=70), recrutados a partir das mesmas áreas geográficas de São Paulo, Brasil. Até o momento, a maioria dos estudos foi realizada em países em desenvolvimento. Metodologia: A investigação utilizou ampla bateria de testes neuropsicológicos composta por 12 testes agrupados em 8 domínios cognitivos destinados a avaliar respectivamente amplitude atencional, velocidade de processamento da informação, memória verbal, memória visual, memória de trabalho, fluência verbal, funções executivas e funcionamento intelectual. O nível de significância foi de p < 0.05. Resultados: O desempenho do grupo de pacientes com psicoses foi pior do que o dos controles em todas as tarefas cognitivas, com diferenças estatisticamente significativas nas tarefas de velocidade de processamento da informação, memória verbal, fluência verbal e funcionamento intelectual, sendo os déficits mais graves no domínio...

Background and Purpose: Functional psychoses are psychiatric disorders which have as their main characteristic a loss of the ability to properly judge the reality due to alterations of thought, perception, emotion, movement and behavior. The main psychotic disorder is schizophrenia, which usually as a chronic and/or deteriorating course in social and occupational relationships, generating enormous personal and financial costs for the patients and their caretakers all over the world. Previous studies have shown the presence of cognitive deficits in patients at the onset of psychoses, more severely in schizophrenia. There are evidences that those deficits are both related to disease processes and to treatment effects. The present work sought to characterize the neuropsychological profile of patients with recent onset psychoses (n=56), up to 3 years after their first contact with Mental Health Service Care 34 with schizophrenia and 22 with affective psychoses. These patient groups had their results compared to a healthy control group (n=70) recruited from the same geographic area of São Paulo City, Brazil. So far, most studies of neuropsychological functioning in patients with recent onset psychoses have been conducted in high-income countries. Method: The cognitive assessment was conducted using a neuropsychological battery comprising 12 tests, grouped into 8 cognitive domains aimed at assessing respectively intellectual functioning, attentional span, information processing speed, verbal memory, visual memory, working memory, verbal fluency and executive functioning. The significance level was set at p < 0.05. Results: The performance of the psychosis group was worse than that of controls in all cognitive tasks, with statistically significant differences detected in information processing speed, verbal memory, verbal fluency and intellectual functioning tasks, most seriously in the verbal memory domain (p < 0.001). When compared against each other...