Abstract:

Future thinking is an important process to psychologically simulate one’s perception of their future. It plays a crucial role in the recovery, persistence and recurrence of depression. Many studies have examined future thinking in depression and found that future thinking is disrupted in depression and is mainly manifested as weakened positive expectations and increased negative expectations for the future. However, the results of the existing studies have not been consistent, which may be due to the fact that ‘self’ in the future events have not been considered in previous research. In the present study, two experiments were conducted to investigate whether the abnormalities of future thinking in non-clinical depression can be modulated by the self in relation to the relevance of personal goals. For this purpose, the present study focused on comparing four different kinds of future events: future positive events either related or unrelated to personal goals, and future negative events either related or unrelated to personal goals.
In Experiment 1, the future thinking task (FTT) was utilized; 23 non-clinical depressive subjects (whose BDI score was higher than or equal to 14) and 25 non-depressive subjects (whose BDI score was not higher than 4) were enrolled. The subjects were required to think about positive and negative future events that could happen to them in the next ten years, either related to or unrelated to their personal goals. After the FTT task, the subjects were asked to evaluate the likelihood that the events would occur to them in the future based on a 50-point Likert scale (1: not at all likely to occur, 50: extremely likely to occur). In Experiment 2, the likelihood estimation measure (LEM) paradigm was used, in which the four types of events were produced according to the interview with the participants before the formal experiment, and the subjects were instructed to evaluate the likelihood that the given events would occur to them in the future based on a 50-point Likert scale as in Experiment 1.
Results of Experiment 1: The results of Experiment 1 showed that the depressive group imagined fewer positive events related to personal goals compared with the non-depressive group. In contrast, there were no significant differences between the two groups in the imagination of the other three types of events. Additionally, the depressive group (in contrast to the non-depressive group) considered that the positive events related to personal goals were less likely to happen to them, whereas negative events related to personal events were more likely to happen to them. This difference was restricted to events related to personal goals, as we did not observe a significant difference between the two groups in evaluating the likelihood of positive and negative events that were unrelated to personal goals. Results of Experiment 2: The results of Experiment 2 showed that the depressive group (in contrast to the non-depressive group) perceived the personal goal-related positive events to be less likely to occur to them. When assessing the likelihood of the negative events presented, the depression group (as opposed to the non-depression group) considered these events to be more likely to happen to them, whether the events were related to the personal goals or not.
Taken together, the results of the current study demonstrated that (1) the abnormality in future thinking of positive events in non-clinical depressive individuals appears to be modulated by the relevance of the personal goals, and (2) the non-clinical depressive individuals showed an abnormal increased in future expectancy of negative events, regardless of whether personal goals were involved. In conclusion, our data demonstrate a deficit in the future thinking of positive events specifically related to personal goals in non-clinical depression. Our study thus shows that the relevance of personal goals is an important factor when investigating future thinking in depression.

Key words: depression, future thinking, personal goal, emotion, likelihood estimation