Brain Changes and Negative Symptoms in Schizophrenia

Abstract

Negative symptoms (and cognitive impairments) in schizophrenia are a correlate of early onset and poor outcome. It is plausible that they are related to an arrest of brain development, for which there is now considerable evidence, but the precise relationship is elusive. In one post-mortem study negative symptoms were related to a reduction in brain length and in an MRI study to an asymmetry of sulcal CSF. It is proposed that the phenomena of psychosis (including negative symptoms) can be understood as part of the diversity of human personality structure generated by a process of sexual selection acting on a sexual dimorphism for cerebral asymmetry.

Global brain asymmetry is increased in schizophrenia and related to avolition

“…Studies examining potential associations between cerebral asymmetry and negative or affective symptoms are scarce, although these symptoms have been shown to have important clinical and cognitive effects in schizophrenia. Even though results are inconclusive, it seems that both negative symptoms and depression are associated with loss of asymmetry .…”

Acoustic and temporal analysis of speech: A potential biomarker for schizophrenia

“…Positive symptoms, such delusions and hallucinations are those that appear to reflect an excess or distortion of normal functions [2] . Negative symptoms, such as loss o nterest or asociality, are those that appear to reflect a diminution or loss of normal functions [3][4][5] . Disorganized speech, a positive symptom is characterized by tangential, loosely associated, or incoherent speech severe enough to substantially impair e communication.…”

Schizophrenia TreAtment with electRic Transcranial Stimulation (STARTS): design, rationale and objectives of a randomized, double-blinded, sham-controlled trial

“…2 Serviço Interdisciplinar de Neuromodulação (SIN), Departamento e Instituto de Psiquiatria, Hospital das Clínicas, Faculdade de Medicina, USP, São Paulo, SP, Brazil. 3 Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBioN), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil. 4 Laboratório de Neuroimagem (LIM-21), Departamento e Instituto de Psiquiatria, Hospital das Clínicas, Faculdade de Medicina, USP, São Paulo, SP, Brazil.…”

“…functionality, lower IQ, and poorer clinical outcome. [3][4][5][6][7] Negative symptoms have a clinical course independent from positive symptoms, are stable or increasing in severity over time, and have an independent prognostic weight. [3][4][5][6][7] Although antipsychotic medications are an effective treatment for positive symptoms and are always recommended for schizophrenia, negative symptoms tend to persist or even worsen in the presence of antipsychotic medication treatment, and no effective treatment for negative symptoms has shown strong supportive evidence.…”

“…[3][4][5][6][7] Negative symptoms have a clinical course independent from positive symptoms, are stable or increasing in severity over time, and have an independent prognostic weight. [3][4][5][6][7] Although antipsychotic medications are an effective treatment for positive symptoms and are always recommended for schizophrenia, negative symptoms tend to persist or even worsen in the presence of antipsychotic medication treatment, and no effective treatment for negative symptoms has shown strong supportive evidence. 8 Evidence for the pathophysiology of negative symptoms points to the involvement of the dorsolateral prefrontal cortex (DLPFC), as neuroimaging studies have shown reduced metabolism in the prefrontal cortex in patients with schizophrenia both with and without medication, 9,10 along with an inverse correlation between negative symptom severity and cerebral blood flow in the prefrontal cortex.…”