Pleasure and poison: Unraveling the relationship between reward sensitivity and psychopathology

This thesis explores reward sensitivity - how much we are drawn to rewards. Imagine it like a magnet pulling us towards things we enjoy. Those who are more sensitive to rewards tend to seek out new experiences and take risks. However, being either too sensitive or not sensitive enough to rewards may also lead to problems. Therefore, we investigated how this tendency might be connected to mental health problems. First, we examined how reward sensitivity might change as we grow old. It seems that reward sensitivity decreases as we age, but in young adulthood, it gets stronger, especially in men. We also found that reward sensitivity is connected to mental health problems differently across ages depending on the type of problem and reward sensitivity predicted some future mental health problems. Genes seem to also play a role in this – some people are genetically more prone to seek rewards and thus might be more vulnerable to mental health problems. Furthermore, we found that parents can pass down to their children characteristics related to reward sensitivity, such as being outgoing or anxious, influencing their children's personalities and mental well-being. Taken together, these findings enhance our understanding of how our relationship with rewards can impact our mental health. The next step is to establish whether reward sensitivity is causing these mental health problems. If that is true, we can then develop better ways to prevent and help people struggling with mental health problems.