The goal of this single-arm pilot clinical trial is to evaluate whether a group-based mindfulness intervention can improve mental health and sleep among parents who are informal caregivers of children with autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD). The main questions it aims to answer are:

Does participating in an 8-week mindfulness program reduce symptoms of stress, anxiety, depression, and insomnia in caregivers? Does participating in an 8-week mindfulness program improve mindfulness in caregivers? What are the caregivers' experiences in participating in the 8-week mindfulness program?

Participants will:

• Attend weekly group-based mindfulness sessions for 1.5 hours over eight weeks.
• Complete assessments before starting the program (baseline) and immediately after the final session.
• Participate in a qualitative feedback interview after the final session.

Inclusion Criteria:

1. Chinese aged at least 18 years old;
2. Written informed consent of participation in the study is given by the participant
3. Willing to comply with the study protocol
4. having a child with neurodevelopment disorder (e.g., ASD, ADHD)

Exclusion Criteria:

1. having been enrolled in any other clinical trial or investigational product within one month at the entry of the study, or having extensive experience in mindfulness practice
2. In the opinion of the research clinician, having a clinically significant suicidality (presence of suicidal ideation with a plan or an attempt)
3. Currently receiving any structured psychotherapy
4. With a hearing or speech deficit