A psychophysiological examination of the mutability of Type D personality in a therapeutic trial

Identifying the associations between health and personality has been a focus for psychophysiological research. Type D personality is associated with predisposition to physical and psychological ill-health. This statistician-blind parallel-group controlled trial (intervention group vs. waiting list control group) examined the impact of Havening Techniques on the Type D constituents of negative affect (NA) and social inhibition (SI). One hundred twenty-five adult (18+ years) participants in the United Kingdom (72 females, 53 males) completed the Type D Scale-14 (DS14) measure of Type D personality at baseline (T1), 24-hours (T2), and at 1-month (T3). Forty participants in the treatment group received additional stress biomarker assessment of heart rate, blood pressure, and salivary cortisol. Type D caseness remained stable in the waiting list participants (n = 57). In the treatment group (n = 68); NA, SI, and total scores decreased from T1 to T2 (p <.001, p <.001, and p <.001, respectively), and from T2 to T3 (p =.004, p <.001, and p <.001, respectively), significantly transmuting to non-caseness (p <.001 for T1 to T2; p =.025 for T2 to T3). Between T1 and T2, decreases in cortisol (p <.001), diastolic blood pressure (p <.001), and systolic blood pressure (p <.001) were demonstrated. Heart rate fell nonsignificantly between T1 and T2 (p =.063), but significantly from T1 to T3 (p =.048). The findings of this study indicate the potential mutability of the psychophysiological illness-prone characteristics of Type D personality.