Journal of Abnormal Psychology vol:124 issue:1 pages:27-37
Background: Childhood trauma and stressful life events increase the risk for psychosis and daily life stress drives moment-to-moment variation in psychotic intensity. Positron emission tomography (PET) studies suggest that prefrontal dopaminergic activity mediates the response to an experimental stressor. It is not known how alterations in this dopaminergic response, associated with psychosis, relate to real-life stress-response in momentary assessment studies. This study is the first to combine [18F]fallypride PET with an Experience Sampling ambulatory assessment approach to examine the association between prefrontal dopaminergic stress response and real-life psychotic reactivity to daily stress.
Methods: Healthy first-degree relatives of individuals with a psychotic disorder (N=14) and healthy controls (N=11) participated in (i) a psychosocial [18F]fallypride PET stress paradigm and (ii) an experience sampling study, using a structured diary approach. Results: Mixed multilevel random intercept models revealed that stress-induced [18F]fallypride displacement, indicative of dopaminergic activity, in ventromedial prefrontal cortex was associated with psychotic reactivity to daily life stress in the entire sample, lower levels of [18F]fallypride displacement to stress predicting increased psychotic reactivity to daily life stress.
Conclusion: Ecological measures of daily life stress-response are associated with experimental measures of altered stress-related prefrontal dopaminergic activity. The dose-response association between these measures suggests that daily life stress responses may be mediated by the prefrontal dopamine system. Alterations in the dopamine system associated with (risk for) psychosis may mediate psychotic reactivity to daily life stress. The findings are compatible with a model in which the dopamine system and hypothalamus-pituitary-adrenal axis mediate a process of sensitization to everyday life stress.