Effects of Guided Relaxation Technique on Symptoms of Anxiety: A Combined EEG-ECG-Respiration Study
Generalized anxiety disorder is considered one of the most serious public health problems in Europe, affecting 9 million people annually . Many psychiatric disorders in general, and anxiety in particular are accompanied by somatic symptomatology. Anxiety is associated with an increase in respiratory activity, heart rate, perspiration, etc. It is a matter of ongoing investigation what are the mechanisms linking mental and somatic symptoms of anxiety . Recently, theoretical models have been proposed suggesting that peripheral physiological systems (e.g., respiration) may act as top-down regulators of neuronal activity . It therefore follows methods of guided relaxation might be able to make use of such mechanisms to alleviate the physiological symptoms of anxiety. Our research goal was to empirically test the efficacy of a guided relaxation protocol used for reducing the symptoms of anxiety and evaluate its potential clinical use by studying the interactions of the neural, cardiac and respiratory activity.
30 men and women aged between 23 and 52 (15 diagnosed with generalized anxiety disorder and 15 healthy controls) participated in the study. Their level of anxious symptomatology was evaluated using MASQ and BCSQ-32 questionnaires. During the session EEG, ECG, PPG and respiration were measured. The session was divided into 6 blocks, each lasting for 10 minutes. The first and last block consisted of a standard EEG resting state recording. In the remaining four blocks participants listened to guided relaxation and/or their synchronous and asynchronous heartbeat. Between blocks, participants' current well-being was estimated with the STAI questionnaire and a blood pressure measurement.
The results of one-way repeated-measures ANOVA showed that both blood pressure measurements and STAI scores were statistically insignificant (p>0.05). Results in the differences in heart rate variability (as indexed by mean R-R interval) were statistically significant for both ECG measurement (F(2.84, 62.4)=3.74, p= 0.017) and PPG measurement (F(2.65, 58.3)=4.41, p=0.010), indicating a possibly positive influence of listening to the heart and guided relaxation on heart rate variability in absence of subjectively perceived improvements.
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