There are various stages of acceptance some of them take time to accept the issues. You can read more about contemplation stage. Seeing a therapist will help. Also explain him that therapy is not just for severe mental issues but also for development and distress.
Next Steps
Help him understand the impact of his depression or emotional issue he is facing
Health Tips
In acceptance cycle the bigger hurdle is denial and may take time but once he sees that due to this his relationships and functionality is impaired he will take actions for support.