Continuous Theta Burst Stimulation for Generalized Anxiety Disorder

Inclusion Criteria: * Age 18 to 65 years. * Right-handed. * Diagnosis of generalized anxiety disorder (GAD) according to ICD-10 criteria (F41.1), confirmed by a psychiatrist. * GAD must be the primary diagnosis and the main reason for treatment at the time of enrollment. Current or past comorbid major depressive disorder will be identified and recorded. * Hamilton Anxiety Rating Scale (HAM-A) total score \>18 at screening/baseline. * Able and willing to provide written informed consent and comply with essential study procedures. * Participants may be psychotropic-medication naïve or may be receiving psychotropic medication. Participants currently receiving psychotropic medication must have maintained the same medication(s) and dose(s) for at least 2 weeks before randomization; for fluoxetine, the required stable period is at least 4 weeks. Exclusion Criteria: * Intracranial or head/neck metallic foreign bodies or implants that constitute a contraindication to TMS or MRI. * Implanted electronic devices such as a cardiac pacemaker, implantable cardioverter-defibrillator, or deep brain stimulator. * Untreated or clinically unstable thyroid dysfunction based on abnormal TSH and/or free T4 levels. * Clinically significant intracranial structural abnormalities that may affect TMS safety, neuropsychiatric presentation, or study neurophysiological measures. * History of epilepsy or seizures, except febrile seizures in childhood. * Bipolar disorder. * Other major psychiatric disorders, including schizophrenia, delusional disorder, or eating disorders. * Acute suicide risk, including clear suicidal ideation or behavior. * Alcohol or substance abuse or dependence within the previous 6 months. * A medical condition associated with a high seizure risk or a history of cranial surgery. * Current use of medication judged by the screening physician to substantially increase seizure risk, or rapid reduction/discontinuation of benzodiazepines, antiseizure medications, or other centrally acting medications associated with withdrawal or increased seizure risk. * Serum vitamin D level \<20 ng/mL that has not been adequately corrected. * Elevated C-reactive protein associated with clinically significant acute infection or acute inflammatory illness that, in the investigator's judgment, may affect participant safety or study outcome assessment. * Pregnant or breastfeeding. * Unable to understand or complete essential study procedures. Participants with potentially reversible temporary exclusion conditions may be rescreened once the condition has been adequately corrected or clinically stabilized.