Abstract
Around 50% of patients with major depression do not respond to standard first-line treatments, such as psychotherapy and pharmacotherapy. At the same time, a subgroup exhibits altered functioning of stress-responsive bodily systems, such as the central locus coeruleus/sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. Given that these systems impact arousal and cognition, it is possible that this subgroup contributes to the high rates of non-responders. Our aim was to investigate whether sympathetic and HPA axis activity modulate treatment outcomes in patients with stress-related major depression. A total of N = 74 inpatients (median age: 50, 62% male) with signs of burnout who fulfilled diagnostic criteria for major depression were recruited. Saliva samples were collected at awakening as well as 30 and 45 min later. Alpha-amylase activity and cortisol concentrations were determined before patients underwent evidence-based multimodal treatment. Non-responders were defined as patients exhibiting a <50% decrease in depression on the Beck Depression Inventory. Non-responders had significantly higher post-awakening alpha-amylase activity than responders (p = .025). In addition, alpha-amylase activity increased significantly over the course of treatment (p = .004), irrespective of responder status. Post-awakening cortisol was neither a predictor nor an indicator of treatment response. If future research confirms alpha-amylase activity as a modulator of treatment response, this may indicate a subgroup of patients with major depression which may benefit from augmentative treatments, such as heart rate variability biofeedback and/or cognitive interventions targeting high arousal.
Pallich, Gianandrea