Having a special needs child is so tough on a marriage. Even a really strong one.
Triangulation: Kids with RAD will reject and defy mom while turning on the charm for dad and everyone else. Mom often looks inept, over involved or harsh. DADS! Do not let your child come between you and your wife. Let your child know that mom and dad are a team that cannot be divided. Dad believes mom's stories and is there for support and to take over regularly so mom can have time to herself.
Conversation: RAD, RAD,RAD, RAD. It can consume a mom. Don't let it consume conversations with your spouse. Talk about the children that are doing well, about common interests or hobbies. Talk about your future after kids.
Fun: Go out and have fun with your spouse without kids. Finding someone who can watch them is worth the difficulty. They may be upset by your going out but you have to do it.
Commitment: We are committed to our kids but first we are committed to each other. Make sure your spouse knows they come first in the family. We need to listen to each other. We need to care about each others feelings.
If all this means you need to get some marital counseling than go! If one of you needs counseling GO! Don't be afraid to ask for help. It is better than just letting things slide.
I'm so thankful for my husband. We have been through some tough times but they have made us stronger! They can do the same for you if you focus on each other and don't let things go.