Event-related potentials in schizophrenia during tonal and phonetic oddball tasks: relations to diagnostic subtype, symptom features and verbal memory

A Ser9Gly Polymorphism in the Dopamine D3 Receptor Gene (DRD3) and Event-Related P300 Potentials

“…In comparison to other European samples, the observed Ser allele frequency of 66.9 in the present study fits well in the expected range of 65.7-71% (Jonsson et al, 2004;Joyce et al, 2003). Comparing our results of P300-amplitude alterations in the Gly9Gly group with the findings in schizophrenia, a parallel in the finding of reduced parietal amplitudes is obvious: reduced parietal amplitudes are the common finding in a large number of studies investigating patients with schizophrenia (Blackwood, 2000;Bruder et al, 2001;Demiralp et al, 2002). However, in previous studies it has been suggested that this P300-amplitude attenuation is most pronounced in a subgroup of patients with early onset, increased risk for tardive dyskinesia and insufficient response to neuroleptic medication (Hegerl et al, 1995;Juckel et al, 1996;Olichney et al, 1998).…”

Fine-tuning risperidone dosage for acutely exacerbated schizophrenia: clinical determinants

“…Etiopathogenesis (Stober et al 1999) and neurophysiological performances (Bruder et al 2001) may also differ between the subtypes. In a similar manner, our high-dose group (with more disorganized patients) showed poorer baseline social and personal-care function than the low-dose group.…”

Theories of Delusional Disorders

“…An impaired frontal processing negativity and mismatch negativity (P1, N1, P2, MMN) was mostly bilateral in paranoid but lateralized in non-paranoid schizophrenics, indicating that the paranoid patients retained a better preservation of the frontal-temporal dialogue in distinguishing relevant from irrelevant stimuli [44] . Together with better verbal skills, application of phonetical versus tonal stimuli leads to greater frontocentral N2 peaks with left-hemisphere dominance in paranoid schizophrenics [45] . However, disorders of the first stages of information processing (P2) and automatic categorization processing (N2) of non-target stimuli were also found to correlate specifically to hallucinations and delusions [37] , which may indicate subtle early attentional deficits as an underlying factor.…”