Autochthonous experience, heightened awareness, and perception distortion in patients with schizophrenia: A symptomatological study

'Early symptoms of schizophrenia' (ESS) proposed by Nakayasu, are present during schizophrenic prodromal periods. Some of these symptoms can continue after the florid manifestation of the disease and the patients often experience them with ego-alien feelings. Autochthonous experience, heightened awareness, and perception distortion (AHP) were selected from the list of ESS. The aim of this study was to confirm both prevalence and specificity of AHP in patients with schizophrenia as well as the relevance of the presence of AHP to symptomatology of schizophrenia. A structured interview was conducted to identify the presence of AHP in three groups of subjects; a schizophrenia group (Sc) with 37 patients, an affective disorder group (AD) with 27 patients, and a control group (NC) with 39 people. The prevalence of AHP was compared among the groups. Within the Sc, the relevance of AHP to Brief Psychiatric Rating Scale (BPRS) was assessed. AHP were present significantly more frequently in the Sc. The total scores for BPRS in the schizophrenic patients with AHP were significantly higher than in the patients without AHP. There was close correlation between AHP and BPRS items, with the degree of relevance depending on the form or perceptual domain. In conclusion, AHP were characteristic of patients with frank schizophrenia. To judge whether AHP were adequately specific to frank schizophrenia, further research of larger subjects is needed. Understanding the characteristics of AHP in patients with frank schizophrenia is important in the symptomatological evaluation of schizophrenia.