Promoting Emotional and Autonomic Control Through Guided Breathing Exercises for Emerging Adults With Autism

Inclusion Criteria: * For participants ≥18 years a voluntary written informed consent and for participants \< 18 years a written informed consent from the parents or their legally authorized representative and an informed assent of the participant has been obtained prior to any screening procedures * Male or Female (biological) * Between 16 and 25 years old * Diagnosis of autism as described in the DSM-IV/DSM-5(-TR) Exclusion Criteria: * Participant has a history of congenital heart diseases, diagnosed cardiovascular abnormalities or somatic diseases conditions that may interfere with the main outcome measure HRV or with the safe practice of breathing exercises (e.g., uncontrolled epilepsy, severe respiratory illness) * Presence of contra-indications for participating (intervention and/or assessment): acute agitation and/or severe psychiatric symptoms (psychosis, mania or major depression) and/or active substance use. * The presence of an intellectual disability, defined as an intelligence quotient \< 70, as described in the DSM-IV/DSM-V. * Insufficient knowledge of Dutch language in order to follow instructions and fill out questionnaires. * Female who is pregnant. * Participation in another interventional study, with or without an investigational medicinal product (IMP) or device (IMD). * The use of medication known to affect cardiac modulation (excluding hormonal contraceptives). * Hearing- or vision impairment that cannot be corrected to normal functioning.