HYPNOSIS AND NEUROPHYSIOLOGICAL MECHANISM OF ANXIETY AND STRESS

We often feel stressed or tell ourselves that we are so, that we are anxious. In everyday language we use to attribute negative values to these two phenomena that, actually, were born and evolved for a completely different reason. Stress is in fact a normal and by all means adaptive physiological response that activates when we face unexpected, unpleasant or difficult situations.  Anxiety and stress, when in small doses, produce a great evolutionary benefit: they help us to keep a high level of attention, they allow us to remain alert in dangerous situations, to reach high performances in important events. From a physiological standpoint, stress response emerged as an adaptive reaction to danger. In emergency situations, in fact, it is useful to activate the organism by increasing the arousal state, enhancing strength, muscular resistance and reflexes. To do so our body, and more specifically a part of our autonomous nervous system (that is the sympathetic, or orthosympathetic nervous system), stimulates bronchodilation, vasoconstriction, tachycardia, sweating. When, instead, there are no dangers around, the parasympathetic component of the autonomous nervous system, which is responsible for bronchoconstriction, vasodilation, salivary function, and of the innervation of the digestive system, is predominant. Thus, It is clear that this system evolved to let us face dangerous situations. However it is also clear that, an elevated level of stress and anxiety can have opposite effects on the body that can lead to anxiety disorders. In these situations, the sympathetic nervous system is activated with no real reasonup to the point that the management of the physical consequences of this activation can become problematic. Anxiety and stress also have a “higher level” correlate connected with the activation of the autonomous nervous system. That is cognitive elaboration. Several subcortical (such as the amygdala) and cortical (especially in the frontal lobes) brain areas are involved in the conscious elaboration of anxiety and stress, and can strengthen physical signals that come from the body.
In managing anxiety and stress, hypnosis produced excellent results, especially when paired with cognitive-behavioral therapy strategies. And interesting case is the Acute Stress Disorder (ASD): this disorder appears a month after a traumatic experience and is characterized, among other symptoms, by a reduction of emotional responses and concentration. The ASD diagnosis is also used as a predictor of Post-Traumatic Stress Disorder (PTSD). In a study conducted on 87 trauma survivors with ASD diagnosis, an integrated strategy based on cognitive-behavioral therapy and hypnosis was applied1. At the beginning of the study, participants were randomly assigned to three different groups: a group attended to a traditional cognitive behavioral therapy without participating to any hypnotic intervention, a group received hypnosis sessions along with cognitive behavioral therapy and the last group received supportive counseling sessions without any psychotherapeutic intervention. At the end of the treatment period and after six months since the end of it: both groups who attended to psychotherapeutic sessions had greater reductions of symptoms compared to the group who only attended psychological counseling sessions; furthermore, a smaller number of subjects assigned to the first two groups developed symptoms that lead to the diagnosis of PTSD. This research also showed that, between the psychotherapy groups, the group that participated to hypnosis sessions showed a greater reduction of symptoms in the months following the end of treatment.
Even without considering deep social or military traumas, everyday life unfortunately contains anxieties that are difficult to avoid. As an example we can use those that are related to hospitals and healthcare environments. For instance, the hated dentist checkup is an event that induces a certain level of anxiety. Several electro-physiological parameters of a patient who underwent to two different operations to install dental implants were analyzed in an interesting study aimed to investigate the effectiveness of hypnosis in treating “dental anxiety”2. Before the first operation, the patient attended to an 80 minutes hypnosis session to reduce anxiety while the second operation had no hypnotic preparation. In both situations, before and after the operation, several parameters, such as blood pressure variations, heart and respiratory rate along with the variation in cerebral activities (measured by using an electroencephalograph, EEG), were recorded. Thanks to the latter measure, researchers observed the presence of Theta waves (slow waves typically associated with sleep) during the hypnotic relaxation conditions. The results of this study showed that vital parameters (blood pressure and heart rate) had significantly lower values before and after the first operation compared to the second one. The authors believe that the relaxation effect following hypnosis sessions can be compared to the sedative effects of an anesthetic (Midazolam) that is typically used before surgical operations. From a more qualitative standpoint, after the hypnosis sessions and the subsequent operation, the participant also showed a variation of his perception of the “dentist's chair”, showing less anxious symptoms related to possible future surgical treatments. Notably, as the authors believe, this kind of hypnotic treatment represents a non-invasive mean to achieve relaxation without collateral effects.
 
This last example is important not only for the achieved results, but, more significantly, because of the methodology that was used in the research: in fact it considered objective physiological parameters that are “close” to our nervous system along with other subjective measures that are extremely relevant when dealing with human neuroscience research. Future research about the use of hypnosis should increasingly use this method to build a bridge between “body and mind”: words that are inextricably bond when dealing with anxiety and stress.
 
 
[1] Bryant RA, Moulds ML, Guthrie RM & Nixon RDV. The Additive Benefit of Hypnosis and Cognitive–Behavioral Therapy in Treating Acute Stress Disorder. Journal of Consulting and Clinical Psychology 73(2); 334 – 340 (2005).
[2] Eitner S, Shultze-Mosgau S, Heckmann J, Wichmann M & Holst S. Changes in neurophysiologic parameters in a patient with dental anxiety by hypnosis during surgical treatment. Journal of Oral Rehabilitation 33; 496 - 500 (2006).
HYPNOSIS AND NEUROPHYSIOLOGICAL MECHANISM OF ANXIETY AND STRESS