My pre-teen is over anxious about thieves

My 13-year old is on ADHD medication. Now he has a strange, problem, which I don’t think is related to ADHD or medication. He starts getting tensed by nightfall. The reason, he fears sleeping alone. We somehow pacify him or stay in his room until he falls aleep and then retire to our room. By then we become really tired. Then by midnight he is knocking at our door. However we try to pacify him, he insists on sleeping in our room.

One night, he woke me up and silently signaled to me that there was someone under our bed. I said, no, no one’s there. But he wouldn’t believe. Very reluctantly he looked under the bed. Seeing the fear on his face, I almost expected someone to be there. Then he frantically started opening our wardrobes to check for someone hiding in there, right in the middle of the night. Finally he fell asleep. But then he insisted on sleeping near my husband and held on to him until he fell asleep.

I can’t describe the thoughts that crossed my mind. I was really shaken. I have heard about various disorders that could accompany ADHD. But, his psychiatrist ruled it out. He said, the child would grow out of it. He has had similar fears in the past too and he recovered from that. May be he is a bit too sensitive. I hope he gets over this sooner.