Abstract
Schizotypy, a set of dispositional traits indicating subclinical risk for schizophrenia, is a key predictor of suicidal ideation. This thesis explores the role of anticipatory pleasure—the expectation of future enjoyment—as a key explanatory factor in the relationship between schizotypy and suicidal ideation across four studies.
In Study 1, I conducted a prospective, month-long study to investigate how anticipatory and consummatory pleasure influenced the relationship between schizotypy and suicidal ideation. Results revealed that anticipatory pleasure, but not consummatory pleasure, fully mediated this relationship in individuals with more schizotypal traits, particularly interpersonal and disorganised schizotypy. These findings suggest that deficits in anticipatory pleasure play a crucial role in suicidal ideation for those at high risk.
In Study 2, I further dissected the construct of anticipatory pleasure in a cross-sectional mediation study, finding that negative expectancy appraisals and defeatist performance beliefs fully mediated the relationship between schizotypy and suicidal ideation. That is, individuals with negative schizotypy who held (1) fewer positive expectations about the future and (2) more defeatist attitudes about their own abilities were more likely to report suicidal ideation. In Study 3, I further explored the multidimensional construct of anticipatory pleasure within the context of schizotypy and suicidal ideation using network analyses. This analysis provided evidence for the central role of negative expectancy appraisals and defeatist performance beliefs in the network, suggesting that interventions targeting these dysfunctional beliefs could potentially mitigate suicidal risk.
In Study 4, I tested a therapeutic manipulation of episodic future thinking (EFT-P) to enhance anticipatory pleasure beliefs. A six-week, single-masked randomised control trial was delivered online. Participants in the EFT-P intervention group showed a stronger decrease in their tendencies to devalue and not expect pleasure over time than the control group, and participants showed significant reductions in both passive and active suicidal ideation over time between groups. Decreases in passive suicidal ideation in the EFT-P group were most pronounced in individuals with high interpersonal and disorganised schizotypy traits.
These studies provide insight into the mechanisms linking schizotypy and suicidal ideation, with important implications for targeted interventions aimed at improving episodic future thinking, future-oriented beliefs, and anticipatory pleasure.