as salaam alaykum. in the west, many muslim have substance abuse issues (drugs/alcohol). how can they be advised? especially when most of the disobedience stems from pain and sadness?

Advise them with good words and a gentle manner, without harshness, and keep repeating the advice. Remind them that intoxicants are from the major sins, and that tawbah is regret, quitting, and resolving not to return. Help them away from those who drink and toward righteous company, as Imam Ibn Baz advised. For the sadness, Shaykh Ibn Uthaymin advised much remembrance of Allah and the du’a, la ilaha illa anta subhanaka inni kuntu min al-zalimin.