 My Brother in-law age early 20s, is moving in with us next week away from his home town, friends and immediate family. I care about him and would like to help in anyway shape or form but im unsure of how to help him along his journey.

He is diagnosed with bipolar and schizophrenia. From what I have heard he's been having hallucinations and is convinced his best friend that has recently passed away, has been coming and talking to him each day. My Wife is very close with him and has been strongly supporting him in through this.

Back in his home town he's been drinking and smoking weed everyday, also while I was with him a month ago was snorting coke quite frequently throughout the day. This has led to him not showing up for work for the past month and fighting with is very mentally-ill and troubled girlfriend. He has not been taking medication to treat his illness thus far.

I have 2 kids ages 4 and a 6 months and wife 24. Im 28, I myself have been diagnosed with depression and im on medication which, I feel, has given me a chance to take control of my life. 

His plans when moving here, is to enter into a drug and alcohol rehabilitation program for 10 days. He will then be living with us for a total of 6 months after. 

I am unsure what the impacts and issues We could face when he has troubles, and am asking in search of advice on my situation. I feel I should set boundaries in place around alcohol and drugs but also do not want to loose his trust in me. My most important things in my life are my kids and family and would do anything to keep them safe. Please help. 

Thankyou.