My best friend of 25 years died 4 years ago and I still think of him at least once a week, wishing I could talk to him. It was almost a year before I could even talk about him without completely breaking down. I never once thought: "oh, this is a medical issue". It was just me having the same problems processing my grief that American men have because we're not raised to talk stuff out. Once I did start talking about it, it got easier and easier to deal with.
I still miss that guy, though.