Thank you to everyone who responded, activities are something my husband and I are suggesting to his mom. He is currently being homeschooled, public school gave him to much anexity and he had some terrible experiences with bullying, which led us to decide homeschool was the best option for him. But they have yet to put him in activities, we've been pushing since the last of last semester. Hopefully we can reach an agreement, he does currently see a therapist, but in recent months he's become very closed off to him, says the same things he is sad and doesn't know why, and doesn't want to try and find out why.

Along with inquiring with the school have him be evaluated with an agency in his area to get a Mobile Therapist to work with him. MT is used for social skills and helping them in important areas of of life.
Another good idea is finding an extra curricular activity he would like. Yes, they need the push. But within time he would like it. It's OT & socialization all in one. Maybe he'd like Karate, swim, baseball etc. In time both the MT & the activity will make positive changes in many important areas of life. I have examples on my profile of different activities I've used on my daughter throughout the years and how they've helped her. She's 16, been mainstreamed, and is on the cheer squad. Very good with communication and accepts changes in life much better.

I believe he needs therapy, i would recommend family therapy that way you can all work together. It must be hard for him to transition from moms house to dads house. How are things for him at school?

welcome to the group! My son went through this is well. It was hard for him to even get out of bed and go to school, and he started avoiding it. I took it very seriously, and I would encourage you all to do the same. I took my son to the emergency room, after I called asking for help. They have a crisis line, and they were very encouraging to bring in my son, if he would come. They told me where to go, and they already had his name, so they were prepared for our arrival. He was called back very quickly to the crisis area. He was evaluated there, and they determine what is best for the child. Most hospitals don't keep children for psychiatric help on the premises, so they will let you know what and where he can get help.
They can transport, via ambulance to a facility that works with minors. It felt awkward to my son, but he said the guys driving him were super nice and helpful. Please contact the school if the mom won't address it. It is important that he gets help, and is not left alone. The school can make a move to help him. Hope he gets help soon.