The structure of negative psychotic symptoms before and after antipsychotic treatment

Poster A21, Monday, October 8, 11:30 am - 1:00 pm, Essex Ballroom

Arsime Demjaha1, Silvana Galderisi2, Celso Arango3, R Rodriguez-Jimenez4, A Mucci2, J Bobes J5, D Stahl1, Paola Dazzan1, Philip McGuire1; 1Department of Psychosis Studies,IOPPN, KCL, 2University of Naples SUN - Department of Psychiatry, 3Hospital General Universitario Gregorio Marañon, 4Instituto de Investigación Hospital 12 de Octubre, Madrid; CIBERSAM, 5University of Oviedo- Department of Medicine

Background Factor analytic studies consistently report two domains of negative symptoms: Expressive Deficits (ED) and Social-Amotivation (SA), but little is known about their stability in relation to medication. Research to date has focused on chronic and medicated samples. We examined whether this two-factor model of negative symptoms can be confirmed in medication naïve first episode psychosis (FEP) patients, and its stability following antipsychotic treatment. Method The sample comprised 469 FEP patients recruited through Optimise Trial (Optimization of Treatment and Management of Schizophrenia in Europe). Confirmatory Factor Analysis (CFA) was performed on negative symptoms ratings, obtained prior to starting medication, by using the Positive and Negative Syndrome Scale (PANSS). Based on published research the following symptoms were included: Flat affect (N1), Emotional withdrawal (N2), Poor rapport (N3), Passive social withdrawal (N4), Lack of spontaneity (N6), Mannerisms and posturing (G5), Motor retardation (G7), G13 Avolition (G13), and Active social avoidance. (G16). The previously identified factors SA (N2, N4, G16) and DE (N1, N3, N6, G5, G7, G13) were entered as latent variables. Multiple indices were used to measure the goodness-of-fit (GOF): the Comparative Fit Index (CFI), The Goodnes-of-Fit index (GFI), the Tucker-Lewis index (TLI), the Root-Mean-Square-Error-of-Approximation (RMSEA). Results The CFA indicated a good fit for two-factor model of negative symptoms. The GOF indices were: CFI = 0.98, GFI = 0.97, TLI = 0.97 and RMSEA = 0.06 (CI 90%: 0.04–0.08). Both SA and DE dimensions remained the same post-treatment. Conclusion Our results demonstrate that the two-factor structure is supported even in medication naïve patients with first episode psychosis, and is unaltered by medication.

Topic Area: Diagnosis and Phenomenology

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