Discriminant validity of low positive affect: is it specific to depression?

The aim of this study was to reveal the effects of low Positive Affect on depression symptomatology. Due to the high correlations between depression and anxiety scores, it was also aimed to present a discriminative validity for these symptomatologies. The study was conducted with 81 university students, who were available during follow-up assessment as well. Consistent with expectations, analyses revealed that low Positive Affect predicted changes in depression symptomatology but did not predict changes in anxiety symptoms. Regarding Negative Affect, although zero-order correlations and hierarchical regression revealed Negative Affect as related with depression and anxiety measures; more conservative hierarchical regression equations where the changes of these symptomatologies were tested, by controlling for the variance accounted for by the changes in counterpart symptomatology, the effect of Negative Affect did not remain to be significant on either measure. Implications of these results were discussed in terms of their relevance to positive–negative affect and tripartite models, and also discriminative value of low Positive Affect for depression and anxiety measures was underlined.