Hmmm intelligence imo means there are plenty of ways he can distract himself from the depression... but he still needs to investigate why he's depressed.
I'm thinking he's caught in the stereotypical thinking that real men don't go to psychologists or do therapy

Maybe by assuring him to maybe consult with a male therapist, and ask HIM for ways he can combat his depression will give the T the opportunity to convincing him to continue therapy???
He needs to eat right, get plenty of restorative sleep, have some fun activities, maintain social contacts... but then, if he's depressed, he won't want to do that
You might suggest he go to the MD for a physical... sometimes these things are physically based... plus, if he opens up to the MD about feeling down, the MD might go ahead and prescribe something to help... short term... and without the need for a psychiatrist???
I think you're a great friend for caring... TC