Halloween can certainly be fun for individuals with ASD/DD, as long as you do some preparation for it and address sensory sensitivities. Here are several resources to consider to make your Halloween enjoyable and memorable!
HANDS in Autism®: SENSORY FRIENDLY HALLOWEEN CRAFTS AND GAMES
Autism Speaks: Happy Halloween: Making the holiday fun for everyone
Autism Society of North Carolina: Making Halloween Fun for Individuals with Autism
Autism Society of Greater Wisconsin: Halloween Toolkit
Seattle Children’s Hospital: 8 Tips for a Safe Halloween for Your Child With Autism