A Two-Factor Model Better Explains Heterogeneity in Negative Symptoms: Evidence from the Positive and Negative Syndrome Scale

Abstract

Acknowledging separable factors underlying negative symptoms may lead to better understanding and treatment of negative symptoms in individuals with schizophrenia. The current study aimed to test whether the negative symptoms factor (NSF) of the Positive and Negative Syndrome Scale (PANSS) would be better represented by expressive and experiential deficit factors, rather than by a single factor model, using confirmatory factor analysis (CFA). Two hundred and twenty individuals with schizophrenia spectrum disorders completed the PANSS; subsamples additionally completed the Brief Negative Symptom Scale (BNSS) and the Motivation and Pleasure Scale—Self-Report (MAP-SR). CFA results indicated that the two-factor model fit the data better than the one-factor model; however, latent variables were closely correlated. The two-factor model’s fit was significantly improved by accounting for correlated residuals between N2 (emotional withdrawal) and N6 (lack of spontaneity and flow of conversation), and between N4 (passive social withdrawal) and G16 (active social avoidance), possibly reflecting common method variance. The two NSF factors exhibited differential patterns of correlation with subdomains of the BNSS and MAP-SR. These results suggest that the PANSS NSF would be better represented by a two-factor model than by a single-factor one, and support the two-factor model’s adequate criterion-related validity. Common method variance among several items may be a potential source of measurement error under a two-factor model of the PANSS NSF.

Differential improvement of negative-symptom subfactors after cognitive remediation in low-functioning individuals with schizophrenia

“…In exploratory and confirmatory factor analyses, Liemburg et al (2013) found an “expressive deficit” (or expressive negative) subfactor that includes flat affect (N1 of the Negative PANSS items), poor rapport (N3), lack of spontaneity and flow of conversation (N6), mannerisms and posturing (G5), motor retardation (G7), and disturbance of volition (G13), and a “social amotivation” (or experiential negative) subfactor comprising emotional withdrawal (N2), passive/apathetic social withdrawal (N4), and active social avoidance (G16). This two-subfactor structure using PANSS negative item data from different patient samples was replicated by several other studies (Fervaha et al, 2014; Jang et al, 2016; Khan et al, 2017; Stiekema et al, 2016) confirming the same PANSS items for the social amotivation subfactor. For the expressive negative subfactor, PANSS items were the same across studies except for the PANSS disturbance of volition item (G13), which was included in only two studies (Liemburg et al, 2013; Stiekema et al, 2016), but not in the other three studies (Fervaha et al, 2014; Jang et al, 2016; Khan et al, 2017).…”

The specific social costs of expressive negative symptoms in schizophrenia: reduced smiling predicts interactional outcome

“…hallucinations, blunted affect and formal thought disorder) on a scale ranging from 1 (‘absent’) to 7 (‘severe’) based on a semistructured interview. As both exploratory and confirmatory factor analyses have shown that MNS and ENS are separable factors in the PANSS, we calculated these as proposed in Fervaha and colleagues . Thus, we calculated the ENS factor from the PANSS items N1 Blunted Affect, N3 Poor Rapport, N6 Lack of Spontaneity, and G7 Motor Retardation.…”

Impaired introspective accuracy in schizophrenia: an independent predictor of functional outcomes

“…avolition-asociality), a subdomain of negative symptoms, may impact social outcomes while expression of emotions (e.g. blunted affect) has a much reduced influence (Blanchard, 2006; Foussias, 2010; Harvey, Khan, & Keefe, 2017; Jang, 2016; Kring, 2013). Subdomains of IA: IA and IB of neurocognition preferentially predicts non-social everyday functional outcomes while IA and IB of social cognition most strongly predicts real-world social outcomes (e.g.…”