Emotion processing deficits have been identified as a critical transdiagnostic factor that facilitates distress after trauma exposure. Limited skills in identifying and labelling emotional states (i.e. alexithymia) may present on the more automated (less conscious) end of the spectrum of emotional awareness and clarity. Individuals with alexithymia tend to exhibit a disconcordance between subjective experience and autonomic activity (e.g. where high levels of subjective emotional intensity are associated with low physiological arousal), which may exacerbate distress. Although there is a robust link between alexithymia and trauma exposure, no work to date has explored whether alexithymia is associated with emotional response disconcordance among trauma-exposed adults.

Using a validated trauma script paradigm, the present study explored the impact of alexithymia on emotion response concordance [skin conductance (Galvanic Skin Response, GSR) and Total Mood Disturbance (TMD)] among 74 trauma-exposed adults recruited via a posttraumatic stress disorder (PTSD) treatment clinic and student research programme.

Unlike posttraumatic symptom severity, age, sex, participant type and mood (which showed no effect on emotion response concordance), alexithymia was associated with heightened emotion response disconcordance between GSR and TMD [F(1, 37) = 8.93, p = 0.006], with low GSR being associated with high TMD. Observed effects of the trauma script were entirely accounted for by the interaction with alexithymia, such that those with alexithymia showed a negligible association between subjective and physiological states.

This finding is paramount as it shows that a large proportion of trauma-exposed adults have a divergent emotion engagement profile.