The only permanent and complete cure is for them to stop drinking. The irony is that problem drinkers often spend thousands of pounds on expensive counselling to work out why they are so unhappy so they can in turn stop drinking, but in fact they need to go about things in exactly the opposite way: stop drinking, allow the effects to wear off, then take stock of their lives. They will find that the things they were getting depressed about when they were drinking either cease to worry them or at least become much more manageable and less overpowering.
