Objective: Presence of negative mood (depressed mood) and anhedonia (lack of interest and pleasure) are considered core symptoms of depression, while absence of positive mood is not taken into account. It is therefore remarkable that the depression scales routinely used to assess changes during antidepressant treatment (Hamilton Depression Rating Scale [HDRS], Montgomery-Åsberg Depression Rating Scale [MADRS]) do not really take into account anhedonia. Several scales were developed to assess positive mood and hedonic tone, but they only partially cover the multidimensional concept. Therefore we developed a new 16-item questionnaire, the Leuven Affect and Pleasure Scale (LAPS), to assess negative affect, positive affect, and hedonic tone.
Methods: This first article on the LAPS questionnaire reports on the correlations between the different items, on the factor analysis, and on the differences found in 3 groups of subjects : healthy college students (N=138), depressed but still functioning college students (N=27), and severely depressed inpatients (N=38). These differences were calculated using univariate general linear models with Bonferroni post-hoc testing, and effect sizes were expressed in η2.
Results: Negative and positive affect were only moderately correlated, and the 4 independent variables (cognitive functioning, overall functioning, meaningful life, and happiness) had stronger correlations with positive affect than with negative affect. The major difference in negative affect was between healthy college students and depressed college students, positive affect was different between the 3 groups, and the major difference for hedonic tone was between depressed college students and depressed inpatients. Affiliative positive affect and the affiliative hedonic function were well preserved, even in depressed inpatients.
Conclusions: This preliminary report suggests that the LAPS offers a comprehensive assessment of negative and positive affect, of hedonic tone, and of independent variables (cognitive functioning, overall functioning, meaningful life, and happiness). Clinically relevant differences in subscores were found in 3 groups of subjects with variable levels of depression (healthy subjects, mildly depressed subjects, and severely depressed inpatients).
Keywords: Anhedonia; depression; interest; negative affect; pleasure; positive affect.