Transcranial Alternating Current Stimulation for Generalized Anxiety Disorder and Insomnia: An Open-Label Pilot Study

Inclusion Criteria: Age between 18 and 65 years; Diagnosis of Generalized Anxiety Disorder (GAD) based on Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria; Diagnosis of chronic primary insomnia; Hamilton Anxiety Rating Scale (HAM-A) score ≥15 at screening, indicating at least moderate anxiety severity; Score \>5 on the Pittsburgh Sleep Quality Index (PSQI); Stable use of antidepressants (SSRI or SNRI) is allowed; Limited use of benzodiazepines (maximum of 10 mg/day diazepam equivalent). Exclusion Criteria: History of mania, hypomania, or bipolar disorder; Contraindications to the use of transcranial stimulation; Active suicidal ideation or suicide attempt in the last 4 weeks; Refractoriness to 3 or more antidepressant treatments; Pregnancy; Other psychiatric diagnoses (e.g., schizophrenia, substance dependence, major depressive disorder); Severe medical or neurological conditions; Anxiety or insomnia secondary to other medical or psychiatric conditions (e.g., hypothyroidism, anemia).