Can Taking Vivitrol Shot Result In Depression?

My son has been sober almost 6 months. He is receiving the vivitrol shot. He thinks it may be making him depressed. He moved to another state to live in a sober house and is having trouble making friends, even in aa meetings. He had been doing pretty good but now says he s hanging by a thread and is close to relapsing. How do I know if the vivitrol is truly making him feel depressed or he just wants to stop it so he can use?