We are truly concerned for your friend's well-being and understand the anxiety you must be feeling. Firstly, we want to remind you that God cares about your friend even more than you do. His love is unfailing, and He is always aware of your concerns. In fact it is only through the salvation Jordan of Jesus Christ that we can be certain of someone be preserved no matter what. It is only by believing him that we can know that our lives are truly in the hands of God and be saved from eternal Physicall death.
The Bible tells us, Trust in Yahweh with all your heart, and do not depend on your wisdom. In all your ways acknowledge Yahweh, and he will make your paths straight Proverbs 3:5-6 WEB. Therefore, we encourage you to trust in God and acknowledge Him in this situation.
Regarding your friend's mental health struggles, we remind you that God is a source of comfort and strength. He assures us have not been given a spirit of fear, but of power, love, and self-control 2 Timothy 1:7 WEB. We pray that your friend will experience God's peace and reassurance.
However, we also want to caution you about the nature of your relationship with your friend. While it is courageous to be supportive, it is essential that your friendship does not become over dependent or more of an empathizer instead of pointing them to the real Answer whicb is the Mercy and Trulth of Jesus Christ.. God tells us to Bear one another's burdens, and so to fulfill the law of Christ Galatians 6:2 WEB. There are systems in place for your friend to get professional help and moving on from a mental health condition. This is not exactly a sin but it is important that this person depend on God rather than you.Depending on anyone other than God is a form of idolatry and we find this decribed in the bible about Isaiah the prophet about idolatry. If this is a romantic relationship then it is easier to fall into sexual sin since there is no formal marriage commitment. We need a formal commitment to marriage or not be alone with another man or woman or encourage deep friendship or emotional support with another boy friend or girl friend. We should be careful not to be alone with another woman if we are men and another man if we are a woman. Out of temptation into a situation of sexual immorality.
He said All of us have become like one who is unclean and all our righteousness is like menstrual rags. We all fade as a leaf; and our iniquities, like the wind, take us away Isaiah 64:6 WEB. In this instance your trying to find your friend and comfort them may not be the best solution.
Let us pray together: 'Father, we come before You in Jesus' name, lifting up both of you in this situation. We seek mercy and grace over any weakness in this. We pray for your friend's safety and well-being, and we ask that You guide them back to us and point towards Jesus Christ's presence and saving grace and ultimately to you and eternal life with you. Please grant them peace, comfort, and healing of their mind. Help them to seek Your wisdom and guidance through the Bible and honest Christian community. Give them the courage to find the appropriate medical and legal assistance available to those in need. We also pray for you, that God would grant you patience and hope regardless of any news(or lack) from your friend. Together we agree that God's will be done in both of your lives and for his everlasting Kingdom. A prayer to any other god, entity, or saint is one of idolatry. The bible wells us that this is an uncleanness and we would view anything said to God at this time as bearing that stain unless this person professing Jesus Christ as Lord and Savior. Satan can appear as an angel of light or as any other image of a shining entity offering false hope. Allow the Holy Spirit and word of God to assure you of this rather than any other medium or mediator the world or any other religion will offer. In Jesus' name, we pray' Amen.
Prayer Focus: God, Thank You for loving me. Thank You for loving me, Jesus. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, soul, mind, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
