My son is depressed but won’t seek help

I can’t help him because he is 21 and has to self-refer, but he insists he is fine even though he has lost interest in most thingsMy 21-year-old son has been depressed since October, but refuses to get therapy. I saw his GP, but was told that, as he is 21, he should seek self-referral. At that time, he had just had a breakdown and was crying uncontrollably. He has since been a shadow of himself, has no appetite and in the evenings feels restless and tired. He is not on any medication. He h