RESUMO
Patients with first episode psychosis (FEP) present with cognitive deficits and volume differences in certain brain areas. Brain volumetric information further correlates with cognitive testing, and multiple brain areas shows different strengths of correlation with the cognitive functions being tested. Traditionally, these cognitive functions are independently related to volumetric differences, but these functions share variance. Failing to account for this aspect of cognition hinders the proper representation of cognition in neuroimaging studies. We used modeling methods which account for this shared variance to investigate the differences of correlations between cognitive abilities and brain areas. A multiple-groups structured equation model (SEM) approach was used to design and test a model representing the relation between gray matter volumetric data and neuropsychological test scores in a sample of 100 Brazilian FEP patients and 94 controls. Models with a latent variable formed by neurological measures and reflecting cognitive measures performed better on fit tests. FEP moderated the relation between gray matter volumes and cognition by altering the profile of correlations between groups. This moderation had a large effect size. SEM provides a fine grained picture of the interdependence of structural brain changes and cognition.
Assuntos
Disfunção Cognitiva/fisiopatologia , Substância Cinzenta/patologia , Modelos Estatísticos , Testes Neuropsicológicos/estatística & dados numéricos , Transtornos Psicóticos , Adulto , Brasil , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/patologia , Transtornos Psicóticos/fisiopatologia , Adulto JovemRESUMO
OBJECTIVE: To identify predictors of misidentification of organic mental disorders and delirium in patients undergoing psychiatric liaison consultation. METHODS: Data were collected at Santa Casa de São Paulo between July of 2009 and March of 2013. We included in our analysis all inpatients for whom the requesting service judged that a psychiatric consultation was required for a possible mental health condition. Outcomes of interest were the instances of misidentification where a condition was initially deemed to be of a psychiatric nature, whereas the final diagnosis by the liaison psychiatric team was of an organic disease or delirium. Our predictors were the clinical specialty of the requesting service, requester and patient characteristics. A series of generalised linear models were used to evaluate misidentification risks. RESULTS: A total of 947 subjects met our inclusion criteria, 14.6% having a final liaison diagnosis of organic mental disorder and 8.1% of delirium. Older patients were significantly associated with increased risk of misidentification for both organic conditions (OR 3.01 - 95% CI 2.01, 4.5) and delirium (OR 3.92 - 2.4, 6.39). CONCLUSIONS: Educational interventions in general hospitals focused on preventing psychiatric misdiagnosis should target in-hospital services where patients tend to be older.