Objective: A case study describing the association between vagal tone and social-emotional adaptation in two distressed adolescent–parent (A–P) pairs during a Positive Cognitive Behaviour Therapy Programme (P-CBTP).
Methods: Two A–P pairs completed a P-CBTP with pre- and post-intervention biosocial-emotional assessments; weekly training sessions over 7 weeks to develop individual strengths, new adaptive cognitions, positive discipline skills, optimism and knowledge on age-appropriate developmental expressions; augmented by moderate physical activity. Resting vagal tone and vagal reactivity were assessed by time-domain measures of vagal activity (RMSSD).
Results: Social-emotional adjustment improved in all A–P pairs. Resting vagal tone increased over the intervention period, from low-to-low-normal towards average-for-normal in three subjects. The fourth individual had excessive pre-intervention resting vagal tone that declined in the direction of normal over the intervention period. Vagal reactivity in response to orthostatic stress remained the same pre- to post-intervention.
Conclusions: Changes in resting vagal tone demonstrated improvements in psychological functioning in all four subjects over the period of intervention. Results supported the view of the association between vagal tone and mental health not being an absolute positive relationship, but that low, as well as excessive, vagal tone may be maladaptive. Indications are that the same may apply to vagal reactivity to psychological stress. More studies need to examine the association between resting vagal tone and emotion regulation in A–P relationships during P-CBTP, keeping in mind that a linear relationship cannot summarily be expected in population studies.