Biological and Psychological Markers After Intervention in Adults With GAD

Biological and Psychological Markers After Trancranial Electrical Stimulation in Adults With Generalized Anxiety Disorder

This clinical trial inestigates the effects of transcranial direct current stimulation (tDCS) on anxiety symptoms in adult women with clinically relevant anxiety levels. The intervention involves the application of low-intensity electrical current over the left dorsolateral prefrontal cortex (DLPFC) across twenty consecutive sessions. Participants are randomly assigned to either an active or sham stimulation group in a double-blind design. The study aims to evaluate changes in anxiety symptoms, emotional regulation, and physiological and molecular markers, including EEG activity, heart rate variability (HRV), and salivary levels of cortisol and interleukin-6 (IL-6) plasma. The findings are expected to support the development of complementary, low-cost, and non-pharmacological strategies for anxiety management.

Anxiety is one of the biggest causes of disability in the world, and many patients do not respond to conventional treatments. Due to this situation, studies were carried out to understand better understand the mechanisms of psychiatric disorders, and one of the alternatives found was the non-invasive brain stimulation with transcranial direct current (tDCS). The project in question aims to evaluate the effectiveness of tDCS-based intervention in adults with anxiety, comparing with a control group. The results will be measured through questionnaires and tests cognitive effects, as well as analyzes of physiological data and inflammatory markers. The study will be done through an experimental and a control group, with 49 men and women in each group. All data will be collected at the Neuromodulation laboratory at Hospital de Clínicas de Porto Alegre, under the coordination of Professor Wolnei Caumo. Participants will be recruited through previously registered patients on Neuromodulation laboratory at Hospital de Clínicas de Porto Alegre database, and the inclusion criteria and exclusion will be defined according to values of anxiety scales and other characteristics of health. The entire process will be conducted safely. Participants in the experimental and control will have their data collected on the first and last day of the intervention. Each participant will receive a placebo or control intervention of 20 sessions, between the first and the last, and will be blinded between groups.

Inclusion Criteria:

• Adults under the age of 18;
• GAD-7 ≥ 10
• Possibility of being present on previously agreed days.

Exclusion Criteria:

• Being in psychopharmacological treatment for depression;
• HAM-D≥23 scale;
• have a self-reported severe disorder (psychosis, schizophrenia, substance abuse, major depression);
• having had seizures and epilepsy;
• having presented substance use disorder (except Tobacco) in the last 6 months or Suicidal Ideation in the last 6 months;
• being pregnant or breastfeeding;
• have suffered any type of brain injury or surgery, heart disease or cranial defect.