ABSTRACT
The identification of the cerebral substrates of psychoses such as schizophrenia and bipolar disorder is likely hampered by its biological heterogeneity, which may contribute to the low replication of results in the field. In this study we aimed to replicate in a completely new sample and supplement the results of a previous study with additional data on this topic. In the aforementioned study we identified a schizophrenia cluster characterized by high mean cortical curvature and low cortical thickness, subcortical hypometabolism and progressive negative symptoms. Here, we have used magnetic resonance images from 61 schizophrenia and 28 bipolar patients, as well as 51 healthy controls and a cluster analysis to search for possible subgroups primarily characterized by cerebral structural data. Diffusion tensor imaging (fractional anisotropy, FA), cognition, clinical data and electroencephalographic (EEG) modulation during a P300 task were used to validate the possible clusters. Two clusters of patients were identified. The first cluster (29 schizophrenia and 18 bipolar patients) showed decreased cortical thickness and area values, as well as lower subcortical volumes and higher cortical curvature in some regions, as compared to the second cluster. This first cluster also showed decreased FA in frontal lobe connections and worse cognitive performance. Although this cluster also showed longer illness duration, there were first episode patients in both clusters and treatment doses and types were not different between clusters. Both clusters of patients showed decreased EEG task-related modulation. In conclusion, our data give additional support to a distinct biologically based cluster encompassing schizophrenia and bipolar disorder patients with cortical and subcortical alterations, hampered cortical connectivity and lower cognitive performance.
Subject(s)
Bipolar Disorder/diagnostic imaging , Bipolar Disorder/psychology , Magnetic Resonance Imaging/methods , Schizophrenia/diagnostic imaging , Schizophrenic Psychology , Adult , Bipolar Disorder/physiopathology , Diffusion Tensor Imaging/methods , Electroencephalography/methods , Female , Humans , Male , Middle Aged , Psychotic Disorders/diagnostic imaging , Psychotic Disorders/physiopathology , Psychotic Disorders/psychology , Schizophrenia/physiopathologyABSTRACT
The application of graph theory measures in the study of functional brain networks allows for the description of their general properties and their alterations in mental illness. Among these measures, connectivity strength (CS) estimates the degree of functional connectivity of the whole network. Previous studies in schizophrenia patients have reported higher baseline CS values and modulation deficits in EEG spectral properties during cognitive activity. The specificity of these alterations and their relationships with pharmacological treatments remain unknown. Therefore, in the present study, we assessed functional CS on EEG-based brain networks in 79 schizophrenia and 29 bipolar patients in addition to 63 healthy controls. The subjects performed a P300 task during the EEG recordings from which the pre-stimulus and the task-related modulation CS values were computed in the global and theta bands. These values were compared between the groups and between the patients who had and had not received different treatments. The global band pre-stimulus CS was significantly higher in the schizophrenia group compared with the bipolar and control groups. Theta band CS modulation was decreased in schizophrenia and bipolar patients. Treatment with antipsychotics, lithium, benzodiazepines, and anticonvulsants did not significantly alter these CS values. The first-episode and chronic schizophrenia patients did not show significant differences in CS values. Higher global band pre-stimulus CS values were associated with worse general cognition in schizophrenia patients. These data support increased connectivity in the whole-brain network that is specific to schizophrenia and suggest a general hyper-synchronized basal state that might hamper cognition in this syndrome.
Subject(s)
Bipolar Disorder/physiopathology , Electroencephalography , Nerve Net/physiopathology , Schizophrenia/physiopathology , Adult , Antipsychotic Agents/therapeutic use , Bipolar Disorder/psychology , Cognition , Event-Related Potentials, P300 , Female , Humans , Male , Middle Aged , Neural Pathways/physiopathology , Schizophrenic Psychology , Theta Rhythm , Treatment Outcome , Young AdultABSTRACT
Los autores presentan una actualización del tratamiento antipsicótico de la psicosis, centrándose en tres aspectos: la elección del fármaco antipsicótico, el problema de la adherencia y los tratamientos aún en fase de investigación. El antipsicótico a elegir en el tratamiento debe tener en cuenta tanto características individuales de cada paciente, preferencias, como características clínicas de la enfermedad. Se revisan las principales guías de tratamiento para hacer una buena elección del fármaco atendiendo al mecanismo de acción y perfil de efectos secundarios, respuesta clínica, fase de la enfermedad, pacientes resistentes, etc. Uno de los grandes problemas del tratamiento farmacológico en la psicosis es conseguir una buena tasa de adherencia al mismo, para ello se revisan las estrategias psicofarmacológicas, psicoterapéuticas y psicosociales que puedan favorecerla. La investigación actual se centra en la búsqueda de nuevos fármacos con características de atipicidad similar a los ya existentes (bloqueo de múltiples receptores, agonismo parcial dopaminérgico), fármacos atípicos ya conocidos con nuevas presentaciones, principalmente de acción retardada que puede favorecer la adherencia y nuevas dianas, especialmente la acción sobre la vía glutamatérgica (AU)
The authors present an update on the antipsychotic treatment of psychosis, focusing on 3 aspects: choice of antipsychotic drugs, the problem of adherence and treatments still being investigated. The antipsychotic drug chosen in the treatment should take into consideration the individual characteristics of each patient, patients preferences and the clinical characteristics of the disease. The principal treatment guidelines in order to make an adequate choice of drug, considering the action mechanism and secondary effects profile, clinical response, disease phase, resistant patients, and so on, are reviewed. One of the most important problems of drug treatment in psychosis is to achieve a good adherence rate. Thus, the psychopharmacological, psychotherapeutical and psychosocial strategies that may favor this are reviewed. Current research focuses on the search for new drugs with atypicity characteristics similar to those that already exist (blockage of multiple receptors, partial dopamine agonism), already known atypical drugs with new presentations, mostly delayed action drugs that may favor adherence, and new targets, especially action on the glutamatergic pathway(AU)
