If the anti-depressants aren't helping, his next steps ought to be exercise and cognitive therapy.
The exercise is useful anyway and gets dopamine flowing through his body. A good wear-yourself-out game of hoops or running or whatever will work up a good head of sweat will help on several levels.
Cognitive therapy is a psychological counseling that does not need any drugs. It helped me through my depression. This fellow is flooded with negative thoughts. What cognitive therapy does is help to break down negative thoughts and examine them as to whether they are true. Most of the time, they are either not true or exaggerated which then become obstacles to corrective behavior.
An example depressed statement: "My work at the office is useless."
The patient is then asked to come up with specific examples where his work was not useless. Then he must re-examine his statement and realize the statement is a lie. Sounds corny but once you train yourself to attack depressing lies the mind tells itself, you can overcome the issues behind the depression.
There are, IMO, two types of depression: one from chemical imbalances that anti-depressants should treat, the other from emotional depression based on negative circumstances. When medication does not appear to help, exercise and cognitive therapy are the next step.
As a recovering alcoholic, he probably also needs a buddy who can hold him accountable for taking a drink. And, as a Christian, a prayer partner is also recommended.
I haven't read all the comments but that's my untrained diagnosis.
Writing things out always forces me to clarify my thinking, sometimes I start out with one premise and by the time I am through, I feel the opposite.
Thanks for sharing...