I'm making that up, after Movember, since I think this takes more men than prostate cancer, which is practically cured now, since they have diagnostics and early treatment with the radioactive beads.
Male depression has no blood test, and a complete aversion. All the worst cases I've seen spout the words "I ain't seeing no shrink!". The toll on family and kids is huge, and we must throw all cases of Fordianism (alcohol, drugs) into this.
In my family of German stock, we have the genetics of people being 'Intellectual Depressives'. This has always ended with a brilliant poet or artist killing themselves at an early age. I pick December since this is the cruellest month for Northern Depressives.
A Depressive is incapable of diagnosing himself, so you have to do it for him. There are countless web sites giving questionnaires that do a good job. Then present him with the facts, and a big gun to his head, to go to the doctor. You've got to do this before he goes down the 'self medication' route of alcohol. Most likely a small amount of a simple pill is all he needs.
You really need the pills to climb out of the hole. There is no 'buck up' here. Once you are out, then you can do things to reduce the pills, like light therapy and melatonin. The pills are needed because a Depressive has brain changes, that need a lot of 'force' to reverse.
If you are under control, then December brings challenges, mainly the parties and drinking. Treat alcohol as being liquid gold. Drink fine wine like liqueur. Make a shooter of half vodka, and half Christmas Port, and fully believe it is the world's most expensive Scotch, and sip it. It has a magnificent finish that lasts a long time. The pleasure really boosts serotonin.