Seasonal Pattern Assessment Questionnaire (SPAQ) ‑ Psychometric characteristics of the Portuguese version

Abstract

Introduction/Objective: Seasonal alterations in mood and behavior characterized by depressive states during autumn/winter and remission during spring/summer are very frequent. In order to identify the sensitivity of the subjects to seasonal alterations, the Seasonal Pattern Assessment Questionnaire (SPAQ) is likely the most used self‑evaluation instrument. The present study evaluates the psychometric properties of the Portuguese version of SPAQ.
Material and methods: The sample was composed of university and professional courses’ students (137 men and 187 women; mean age 27.7 ± 9.8). The analysis of SPAQ focused on items that are part of to the Global Seasonality Score (GSS), and the categorization of subjects into subtypes: without seasonal affective disorder; subsyndromal seasonal affective disorder (S‑SAD); seasonal affective disorder (SAD).
Results: The mean global seasonality score was 9.1 ± 4.3 showing no significant differences between men and women. The internal consistency of the items that constitute the Global Seasonality Score was 0.804 (Cronbach’s α) and the average inter‑item correlation was r = 0.406. In respect to the questionnaire’s answers, 29.0% corresponds to subsyndromal seasonal affective disorder and 12.7% to seasonal affective disorder. Irrespective of the severity, 30.6% of the subjects considered seasonal alterations in mood and behavior a
problem.
Conclusion: The SPAQ proved to be an easy‑to‑use self‑evaluation instrument with good psychometric properties. Considering the sample size, the results suggest that the seasonal variations in humor and behavior are very common. The fact that higher values were found in comparison to other studies conducted in non‑clinical populations highlights the necessity to evaluate the specificity of the questionnaire and conduct studies in representative population samples.