MacLeod, A. K., & Byrne, A. (1996). Anxiety, depression, and the anticipation of future positive and negative experiences.

An experiment is reported that attempts to distinguish between anxious and depressive future thinking in terms of anticipation of future positive and future negative experiences. Anxious, mixed (anxious-depressed), and control participants were given an adapted verbal fluency paradigm to examine the ease with which they could think of future positive and negative personal experiences. Anxious participants differed from controls only in anticipating more future negative experiences; mixed participants showed both greater anticipation of negative experiences and reduced anticipation of positive experiences. Self-report measures of hopelessness and worry followed a similar pattern to future positive and future negative anticipation, respectively. The results are discussed in terms of the distinction between positive affect and negative affect

http://dx.doi.org/10.1037/0021-843X.105.2.286