Aim: Neuroticism, i.e. the tendency to experience negative affects such as stress, depression, and anxiety, can have a significant impact on daily life. The aim of the current study was to investigate to what extent neuroticism impacts the susceptibility to experiencing immune-related diseases.

Methods: Dutch university students were invited to complete an online survey. Neuroticism, immune fitness, and past year’s frequency of experiencing immune-related complaints were assessed. Correlational analyses determined the associations between neuroticism and immune outcomes, and possible sex differences were evaluated.

Results: Data from N = 1790 participants were included. Their mean (SD) age was 21.31 (2.1) years old and 82.2 % of the sample were females. Overall, higher levels of neuroticism were associated with significantly poorer immune fitness (r = -0.227, p < 0.001). Significant correlations were found between neuroticism and sore throat, headache, flu, runny nose, coughing, mild fever, sudden high fever, sinusitis, diarrhea, eye infection, wound infection, and slow healing wounds. However, albeit statistically significant, the magnitude of these correlations was only modest (r < 0.3). Females scored significantly higher on neuroticism (p < 0.001) and reported significantly poorer immune fitness than males (p < 0.001). Females experienced sore throat (p < 0.001), headache (p < 0.001), and eye infection (p = 0.002) significantly more often than males. No sex differences were observed in the magnitude of the correlations, except for the flu, which had a stronger correlation in females than males.

Conclusions: Significant associations were found between neuroticism, immune fitness, and the frequency of experiencing immune-related complaints.