Abstract:
This thesis examined transdiagnostic characteristics of psychological symptoms and how they might affect decision making and performance on a behavior inhibition task. Instead of examining individuals diagnosed with distinct psychological disorders, this study examined the influence of transdiagnostic symptoms, similar across different disorders, measured in the general population. Anxious/depressive, compulsive/impulsive, and social withdrawal were the three dimensions examined in the present study, and are anticipated to play a role in decision-making. Decision-making was measured in this paper using delay discounting techniques. Delay discounting measures the likelihood that an individual will choose a smaller, immediate reward or a larger, delayed reward. It is a measure of impulsiveness that was hypothesized to relate to certain symptoms of psychological disorders. This study also examined behavioral inhibition using a Go/No-Go decision making task. This study used a transdiagnostic dimensions questionnaire, three discounting tasks regarding monetary, social and health rewards, and a behavioral inhibition task. The results showed that age was a good predictor of higher discount rates, with older individuals significantly more likely to choose the smaller, immediate reward. We did not see any significant relationships between the three transdiagnostic dimensions and delay discounting. However, we did see an effect of reaction time and anxious depressive symptoms on the Go/No-Go behavioral inhibition task. Also, age played a role in false positive error, while social withdrawal symptoms played a role in false negative error on the Go/No-Go task. The observed relationship between age and discounting was broadly consistent with previous literature. The lack of an association between transdiagnostic symptoms might reflect the relatively mild levels of symptoms in the small sample used, weaknesses in the symptom measures, and/or this specific measure of decision making.
