Short version of the Profile of Mood States in persons with schizophrenia: Construct validity of the Portuguese version

Objective There is a strong consensus that mood enhancement is a primary benefit of physical activity (PA). However, the evidence about the positive effect of PA on the mood states of persons with schizophrenia is scarce, probably due to the limited psychometric properties of the most widely used instrument to assess mood. Therefore, this study aimed to assess the construct validity of the Portuguese short version of the Profile of Mood States (POMS-SV) for persons with schizophrenia. Additionally, a comparative analyse was conducted to explore the mood states according to different demographic variables. The sample consisted of 106 in and outpatients (n=47 women) with schizophrenia. Methods Cronbach’s alpha coefficient was used to assess internal consistency. Exploratory and confirmatory analyses were carried out to examine the factor structure and structural validity of the questionnaire, respectively. Pearson’s correlations were calculated in order to examine the associations between the POMS subscales. Mann-Whitney and Kruskal-Wallis tests were used to compare means differences of POMS subscales and total scales between sociodemographic groups. Results The Portuguese version of the POMS-SV revealed a model of 31 items and 6 factors with good internal consistency and good fit indexes for the application in persons with schizophrenia. Significant differences were found in gender, marital status, and engaged PA in the negative mood sub-scales. Conclusion The POMS-SF exhibited good psychometric properties and appears to be a valid and reliable instrument to assess mood states in a population of both in and outpatients with schizophrenia. The results of the present study support its application in clinical practice and research with expanded usefulness in PA settings.