Stress Sensitivity and the Extended Psychosis Phenotype: Results from the Experience Sampling Method Study

Individuals with psychosis might show heightened sensitivity to minor daily stressors. However, it is unclear if this sensitivity extends to the broader population with subclinical psychopathology, reflected in psychotic-like experiences (PLEs). This study examined whether individuals with PLEs show increased symptom and cortisol responses to minor daily stressors.

Altogether, 99 individuals with PLEs and 102 controls without PLEs were enrolled from the general population (aged 18-35 years). Using the experience sampling method over 7 days, participants reported PLEs, negative affect, threat anticipation, aberrant salience, and stress across different categories: area-related, activity-related, event-related, and social stress. Saliva samples for cortisol measurement were collected after each prompt.

Participants with PLEs demonstrated significantly greater symptom and threat anticipation responses to all stress categories compared to controls. Aberrant salience responses to stress showed sex differences; females with PLEs exhibited stronger aberrant salience responses to most stress categories compared to males, a pattern not observed in controls. Elevated salivary cortisol levels were found among participants with PLEs (Cohen's d = 0.265) regardless of stress exposure, though this effect varied across stress categories in different models.

The extended psychosis phenotype might be linked to elevated salivary cortisol and heightened responses to minor stressors in affective symptoms and threat anticipation, supporting the presence of increased stress sensitivity in people with PLEs. The observed sex-specific differences indicate that aberrant salience may play a distinct and nuanced role in stress sensitivity among individuals with PLEs, especially in females.