Syndromes of schizophrenia on factor analysis

Abstract

levelstend to increasein the premenstrualperiod in normal women (Rapkin eta!, 1987). Increased5-HT levelsin the premenstrual period may therefore con tribute to the relapsing of the psychosis,especially the negativesymptoms. There is also evidence for the serotoninergic modulation of blinking in animal experiments (Dursun & Handley, l99l)The 5-HT2/5-HT1@ recep tor antagonist ritanserin abolishedblinking induced by intracerebroventricular injection of thryotropin releasing hormone, whereas haloperidol did not (Dursun & Handley, 1991). This experimental data also supports Dr Lovestone's observation about the inactivity of adequate dosage of dopamine antagoniststo antagoniseblinking.

The dimensional structure of first episode psychosis: an exploratory factor analysis

“…The above review seeks to highlight a degree of premature closure and complacency, based in part upon a failure to properly take account of methodological (Soni et al 1992) and conceptual issues . Including affective syndromes alongside the various non-affective syndromes and studying the evolution of all these syndromal patterns from the onset of the disorder in representative first episode cases would be key elements of a less blinkered strategy (Arndt et al 1995 ;Kitamura et al 1995).…”

“…Several additional methodological and analytical issues are relevant to the clarification of the underlying psychopathological dimensions in functional psychosis (Soni et al 1992). They are important because most of them have been overlooked in the body of evidence amassed by Andreasen et al (1995) which claimed ' impressive consistency across studies ' in support of the three syndrome model.…”

Evidence for instrument and family-specific variation of subclinical psychosis dimensions in the general population.

“…The existence of a positive and a negative dimension of the clinical and the subclinical phenotype has been by far the most consistently validated, whereas the evidence for a third disorganization dimension is less compelling in both the clinical and the subclinical domains (Van Os & Verdoux, 2003). As affective symptoms tended to be excluded from the first-generation symptom-analytic studies even though they form an integral part of schizophrenia and other psychotic syndromes (Sax et al, 1996; Soni, Hollis, Reed, & Musa, 1992), more recent endeavors that were less biased by Kraepelinian concerns of dichotomizing affective and nonaffective syndromes included depressive and manic symptoms. These investigations yielded additional dimensions of depressive and manic–excitement symptoms but less consistent evidence of a conceptual disorganization factor (Kitamura, Okazaki, Fujinawa, Yoshino, & Kasahara, 1995; Krabbendam et al, 2004; Lindenmayer, Bernstein Hyman, Grochowski, & Bark, 1995; Lindenmayer, Grochowski, & Hyman, 1995; McGorry, Bell, Dudgeon, & Jackson, 1998; Stefanis et al, 2002; Van Os et al, 1999).…”

Evidence that three dimensions of psychosis have a distribution in the general population

“…Multivariate analyses of psychotic features have consistently yielded clusters of positive, negative and disorganization symptoms, not only in patients with schizophrenia (Bilder et al 1985 ;Liddle, 1987 ;Peralta et al 1992Peralta et al , 1994Grube et al 1998), but also in patients with schizoaffective and other psychotic disorders (Maziade et al 1995 ;Peralta et al 1997 ;Ratakonda et al 1998). As affective symptoms tended to be excluded from these first generation symptom-analytical studies even though they form an integral part of schizophrenia and other psychotic syndromes (Soni et al 1992 ;Sax et al 1996), more recent endeavours that were less biased by Kraepelinian concerns of dichotomizing affective and non-affective syndromes, included depressive and manic symptoms. These investigations yielded additional dimensions of depressive and manic\ excitement symptoms but less consistent evidence of a conceptual disorganization factor (Kitamura et al 1995 ;Lindenmayer et al 1995 a, b ;McGorry et al 1998 ;.…”