If he goes more then 3 months and still cannot attain a full erection then there is more than likely another underlying cause than work stress. The doctors usually in most cases aren't much help since about all they will do is prescribe Viagra or Cialis and possibly worse an SSRI drug. If he has got good insurance he still should go to see a urologist and get checked for a venous leak and rule out a physical cause. Most General Practitioners fail to do all of the blood work nescessary to find the cause normally all they test for is TSH and Total Testosterone. He needs a full hormonal panel plus liver function and possibly a urinalysis for neurotransmitters to get to the bottom of it. If he doesn't want to go through the doctors he can get tested through ZRT lab which is a heck of alot cheaper if you don't have insurance. Good Luck!