This study aims to establish a personalized theta burst stimulation (TBS, an advanced variant of repetitive transcranial magnetic stimulation, rTMS) protocol considering autistic idiosyncrasy (interindividual variability).

Inclusion criteria for autistic adults:

• Autistic adults (≥18 years old), confirmed by Autism Diagnostic Observation Schedule.
• DSM-5 severity level of ASD: level 1 or level 2

Inclusion criteria for typically developing control:

• ≥18 years old without autism spectrum disorder

Exclusion criteria for all participants:

• Previous or current severe neurological disorders, especially epilepsy
• Previous or current severe systemic diseases such as cardiovascular disease, diabetes or hypertension
• Previous or current severe brain injury
• Implementation of metal materials such as a pacemaker or medication pump
• Previous or current severe psychiatric disorders such as schizophrenia, bipolar disorder, severe major depressive disorder or substance abuse
• Pregnancy
• Intracranial space occupied lesions
• Previous brain surgery or central nerve system infection
• Concurrent use of medications which increased the risk of seizure attack
• Participate in another clinical trial within one month
• With damaged skin at the stimulated region
• With multiple sclerosis
• With large ischemic scars
• Have experienced sleep disorders during brain stimulation
• Severe alcoholism
• Concurrent use of antiepileptic drugs
• Uncontrollable migraines due to increased intracranial pressure
• Unsuitable for MRI (e.g. those with claustrophobia)
• Unsuitable for EEG
• DSM-5 severity level of ASD: level 3
• Suicidal ideation within one year

Withdrawal criteria:

• Seizure attack during the study period
• Autistic symptoms worsened obviously during the study period (change of DSM-5 severity level)
• Extreme agitation or irritability during the study period
• Participants request
• Clinical symptoms worsened obviously during study period
• Start to use antiepileptic drugs during study period
• Suicidal ideation or self-harm behaviors during study period