Objectives This study had three aims: 1) to investigate whether cardiovascular responses to laboratory stress and levels of emotional distress were attenuated following written emotional disclosure; 2) to test, in addition to the potential main effects, whether levels of alexithymia moderated the impact of writing; and 3) to examine whether alexithymics who successfully disclosed emotion in their essays would experience positive effects following writing.

Design and methods Eighty-seven participants wrote about their most stressful life experience or about a non-stressful experience, for 15 minutes, over 3 consecutive days. Two weeks later, blood pressure (BP) responses to laboratory stress and levels of emotional distress were assessed. Emotional characteristics of the disclosure essays were analysed with the Linguistic Inquiry and Word Count programme and alexithymia was assessed at baseline using the Toronto Alexithymia Scale-20.

Results Analyses found no evidence in support of the main effects of disclosure on cardiovascular responses to stress or on emotional distress. However, alexithymia was found to moderate the impact of writing such that non-alexithymic participants in the experimental condition reported significantly lower emotional distress 2 weeks later. In addition, alexithymic participants who disclosed a greater number of negative when compared with positive emotion words exhibited reduced systolic and diastolic responses to stress. Conversely, non-alexithymic participants who disclosed more positive and less negative emotion words displayed attenuated BP reactivity to stress.

Conclusions The results of this exploratory study are important as they highlighted, in the absence of main effects, the importance of examining potential moderators of the emotional writing process. These findings may have implications for the development of cardiovascular health interventions.