My brother the past few nights has been up at odd hours (3-5 am) seeming like he is still sleeping but walking and speaking to people that are not there. When my mom talked to him he spoke back as if she could see the people that aren't there. It seems like he is acting out his dream but in the morning when he was awake he also herd someone talk that wasn't there and then saw someone that wasn't there. we dont no if he experimented with a drug that had an effect or if he is developing some type of sleep or mental disorder. please help