Repetitive Transcranial Magnetic Stimulation Modulates Frontal and Temporal Time-Varying EEG Network in Generalized Anxiety Disorder: A Pilot Study

Altered Functional Brain Network Structure between Patients with High and Low Generalized Anxiety Disorder

To investigate the differences in functional brain network structures between patients with a high level of generalized anxiety disorder (HGAD) and those with a low level of generalized anxiety disorder (LGAD), a resting-state electroencephalogram (EEG) was recorded in 30 LGAD patients and 21 HGAD patients. Functional connectivity between all pairs of brain regions was determined by the Phase Lag Index (PLI) to construct a functional brain network. Then, the characteristic path length, clustering coefficient, and small world were calculated to estimate functional brain network structures. The results showed that the PLI values of HGAD were significantly increased in alpha2, and significantly decreased in the theta and alpha1 rhythms, and the small-world attributes for both HGAD patients and LGAD patients were less than one for all the rhythms. Moreover, the small-world values of HGAD were significantly lower than those of LGAD in the theta and alpha2 rhythms, which indicated that the brain functional network structure would deteriorate with the increase in generalized anxiety disorder (GAD) severity. Our findings may play a role in the development and understanding of LGAD and HGAD to determine whether interventions that target these brain changes may be effective in treating GAD.

Update on treatments for anxiety-related disorders

PURPOSE OF REVIEW

This review examines recent evidence that informs the treatment of anxiety-related disorders.

RECENT FINDINGS

In addition to selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and benzodiazepines, agomelatine has demonstrated efficacy in treating generalized anxiety disorder (GAD). Other novel products, such as ketamine, psilocybin and cannabidiol, are in the process of gathering evidence in support of the treatment of anxiety disorders. In psychological therapy, various psychological treatments for anxiety disorders, such as mindfulness-based intervention, acceptance and commitment therapy, psychodynamic therapy, emotion-focused therapy and dialectical behavioural therapy, have been tried. Still, most therapies have not proven superior to cognitive behavioural therapy (CBT). In very preliminary findings: Repetitive transcranial magnetic stimulation (rTMS) was effective in GAD; transcranial direct current stimulation (tDCS) was effective for social anxiety disorder (SAD) and GAD and augmented exposure therapy for specific fears. Internet and mobile-based interventions have comparable efficacy to face-to-face therapy.

SUMMARY

Pharmacotherapy of anxiety disorders is expanding to novel products. Despite trying other psychological therapies for anxiety disorders, most therapies were comparable to but not superior to CBT. rTMS and tDCS were also used and show early promise for GAD, but further studies are needed. Most internet or mobile app based psychological therapies were based on CBT, and some can be considered as alternatives to in-person face-to-face therapy.