Basic Disturbances of Information Processing in Psychosis Prediction

Abstract

The basic symptoms (BS) approach provides a valid instrument in predicting psychosis onset and represents moreover a significant heuristic framework for research. The term “basic symptoms” denotes subtle changes of cognition and perception in the earliest and prodromal stages of psychosis development. BS are thought to correspond to disturbances of neural information processing. Following the heuristic implications of the BS approach, the present paper aims at exploring disturbances of information processing, revealed by functional magnetic resonance imaging (fMRI) and electro-encephalographic as characteristics of the at-risk state of psychosis. Furthermore, since high-risk studies employing ultra-high-risk criteria revealed non-conversion rates commonly exceeding 50%, thus warranting approaches that increase specificity, the potential contribution of neural information processing disturbances to psychosis prediction is reviewed. In summary, the at-risk state seems to be associated with information processing disturbances. Moreover, fMRI investigations suggested that disturbances of language processing domains might be a characteristic of the prodromal state. Neurophysiological studies revealed that disturbances of sensory processing may assist psychosis prediction in allowing for a quantification of risk in terms of magnitude and time. The latter finding represents a significant advancement since an estimation of the time to event has not yet been achieved by clinical approaches. Some evidence suggests a close relationship between self-experienced BS and neural information processing. With regard to future research, the relationship between neural information processing disturbances and different clinical risk concepts warrants further investigations. Thereby, a possible time sequence in the prodromal phase might be of particular interest.

Information processing abnormalities in schizophrenia and bipolar disorder

“…Among the neurocognitive deficits, which were accepted as the core symptoms for both schizophrenia and bipolar disorder (1,2), our study investigated the power of the tests assessing the information processing, which was more prominent for schizophrenia (14) and frequently reported to be markedly associated with its clinical course (19,21), in terms of differentiating patients with schizophrenia, bipolar disorder, and healthy individuals. In the study of Van Rheenen et al (44), information processing was reported to be one of the functions that best distinguished schizophrenia and bipolar disorder patients (besides semantic memory and close memory), consistent with our findings.…”

“…Third, information processing speed was found to be slowed in the unaffected relatives of schizophrenia patients (17,18). Finally, information processing deficits were reported to distinguish individuals at higher risk group for psychosis during clinical follow-up with regard to whether or not they would be diagnosed with psychosis (19). Information processing is also related with many clinical and functional conditions in schizophrenia (20,21).…”

Contributions of Experimental Psychiatry to Research on the Psychosis Prodrome

“…Although the prospective identification of individuals making the transition to full-blown psychosis thus faces major challenges, it is undoubted that the prodromal development commonly starts from subtle changes in perception and cognition and ends up with attenuated and transient psychotic symptoms, respectively, at the verge of manifest psychosis ( 28 ). Furthermore, even though not highly predictive of the further course, negative symptoms appear at very early stages of the prodromal development, thereby even preceding (pre-)psychotic symptoms ( 29 ).…”

“…Furthermore, even though not highly predictive of the further course, negative symptoms appear at very early stages of the prodromal development, thereby even preceding (pre-)psychotic symptoms ( 29 ). Besides psychopathology, however, recent research has suggested that the prodrome can also be validly characterized on other domains, i.e., neurocognition and neurofunctioning ( 28 ).…”

Prediction of transition from ultra-high risk to first-episode psychosis using a probabilistic model combining history, clinical assessment and fatty-acid biomarkers

“… 1 , 8 In addition, specific patterns of cognitive function, particularly deficits in verbal fluency, memory and emotional processing, 9 , 10 as well as impaired general function are associated with a higher risk of transition. 6 , 11 Biological predictors include abnormalities of structural and functional neuroimaging, 12 electrophysiology, 13 , 14 , 15 and genetic 16 , 17 and proteomic markers. 18 Individually all of these predictors are of small effect size and integrative models are required to combine multimodal information in the clinical setting to inform the risk of transition for an individual patient.…”