Self-assessment of negative symptoms - Critical appraisal of the motivation and pleasure - Self-report's (MAP-SR) validity and reliability.

OBJECTIVE

The negative symptom domain remains a major challenge concerning treatment. A valid self-report measure could assist clinicians and researchers in identifying patients with a relevant subjective burden. The Motivation and Pleasure - Self Report (MAP-SR) derives from the CAINS and is supposed to reflect the "amotivation" factor of negative symptoms. We evaluated different aspects of the scale's reliability and validity. This is the first factorial analysis as well as the first analysis of test-retest reliability.

METHODS

We assessed three samples of subjects with schizophrenia or schizoaffective disorder (n = 93) and a broad spectrum of related domains.

RESULTS

We explored a 3-, 2- and 1-factor solution (explaining 50.93, 44.85 and 36.18% of variance, respectively). The factor "pleasure and hedonic activity" consists of eight items and was most robust; the factors "social motivation" and "motivation for work" were problematic. Test-retest reliability of the scale was adequate (r = 0.63, p = .005). Neither the MAP-SR nor the "pleasure and hedonic activities" factor are associated with the PANSS negative symptom scale. There are significant associations with the observer-rated CAINS-MAP scale, experiences of pleasure, and social cognition but none with functional outcome. Discriminant validity could not be established with regards to depression and extrapyramidal symptoms.

CONCLUSIONS

We found that the MAP-SR is adequate to assess anhedonia but is less suitable when assessing motivation. Therefore, we propose using the "pleasure and hedonic activity scale" to cover the "anhedonia" subdomain. We think the "motivation" part of the instrument requires reconstruction.