Clinical high risk and first episode schizophrenia: Auditory event-related potentials

Abstract

The clinical high risk (CHR) period is a phase denoting a risk for overt psychosis during which subacute symptoms often appear, and cognitive functions may deteriorate. To compare biological indices during this phase with those during first episode schizophrenia, we cross-sectionally examined sex- and age-matched clinical high risk (CHR, n=21), first episode schizophrenia patients (FESZ, n=20) and matched healthy controls (HC, n=25) on oddball and novelty paradigms and assessed the N100, P200, P3a and P3b as indices of perceptual, attentional and working memory processes. To our knowledge, this is the only such comparison using all of these event-related potentials (ERPs) in two paradigms. We hypothesized that the ERPs would differentiate between the three groups and allow prediction of a diagnostic group. The majority of ERPs were significantly affected in CHR and FESZ compared with controls, with similar effect sizes. Nonetheless, in logistic regression, only the P3a and N100 distinguished CHR and FESZ from healthy controls, suggesting that ERPs not associated with an overt task might be more sensitive to prediction of group membership.

Early auditory processing evoked potentials (N100) show a continuum of blunting from clinical high risk to psychosis in a pediatric sample

“…Significant differences were followed by 2 × 2 Fisher’s exact tests with Bonferroni corrected p threshold for categorical variables and Student–Newman–Keuls (SNK) tests for continuous variables. Consistent with prior studies (del Re et al, 2015; Salisbury et al, 2010), a one-way ANOVA revealed no significant association between clinical group and N100 mean latency [F(2, 65) = 0.020, p = 0.980]; thus, N100 latency was not considered further.…”

“…van Tricht et al (2015) found increasing blunting of the N100 in CHR individuals transitioning to psychosis, Hsieh et al (2012) found a decrease in N100 amplitude from HC to CHR to first-episode PS patients, and Salisbury et al (2010) found that the N100 blunted from first episode to chronic SZ. However, del Re et al (2015) found similar diminished N100 amplitudes in CHR and PS patients, and others did not find N100 blunting in CHR patients (Bramon et al, 2008; Brockhaus-Dumke et al, 2008; Hsieh et al, 2012). Notably, these were studies of adults.…”

Enlarged lateral ventricles inversely correlate with reduced corpus callosum central volume in first episode schizophrenia: association with functional measures

“…All subjects but one were medicated with second generation antipsychotics. Medication dosage was estimated using chlorpromazine (CPZ) equivalents (see Table 1) (For further subjects’ information see (Del Re et al, 2014; del Re et al, 2015). All demographic and clinical data are summarized in Table 1.…”

Abnormal relationships between local and global brain measures in subjects at clinical high risk for psychosis: a pilot study

“…In the CHR group, prodromal symptoms were assessed with the Scale of Prodromal Symptoms (SOPS; contained within the Structured Interview of Prodromal Syndromes (SIPS) (Miller et al 1999). Additionally CHR symptoms were rated on 10 items from the Bonn Scale for the Assessment of Basic Symptoms that were identified as having high predictive validity for the development of psychosis (Klosterkötter et al 2001) and that are implemented in the Schizophrenia Proneness Instrument, Adult Version (Schultze-Lutter et al 2007) (See del Re et al 2015 for details on CHR inclusion criteria used in the CIDAR study and the study by von Hohenberg et al 2014). Exclusion criteria for the CHR group included the presence of any DSM-IV-TR diagnosis of a psychotic disorder, and substance-induced or other medically induced prodromal-like symptoms.…”