I thought this study was interesting. Amongst Gold medalists (those with more than 50 years of T1D under their belt), relatively few people felt distress (great news!), but those with neuropathy experienced distress 3 times as often as those with other very serious complications, like kidney disease, eye disease and heart disease.
http://www.healio.com/endocrinology/diabetes/news/in-the-journals/{b7bf2691-8bb2-4216-8d55-1ef820b3be18}/neuropathy-associated-with-greater-distress-depression-in-older-adults-with-type-1-diabetes
One possibility is that the depression is caused by the pain, but the authors statistically rule that out.
My theory: both the depression and the neuropathy have some underlying physiological cause, possibly inflammation?
What an interesting study!
I was quite struck (and surprised) by the article’s first sentence:
In older adults with longstanding type 1 diabetes, neuropathy is the strongest predictor of diabetes distress and depression, regardless of the presence of painful symptoms
On the other hand, I was also suprised by this, which I think is really cool:
“Our study shows that older Canadians with type 1 diabetes for at least 50 years have overall low prevalence rates of distress and depression […]”
Hopefully, this is not only true for older Canadians 
yes, to me it really is striking.
Here’s an interesting summary about inflammation and depression:
And of course many types of neuropathy are linked to inflammatory responses:
https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Peripheral-Neuropathy-Fact-Sheet
I also found the relatively low rate of distress quite heartening. I hope my son can have such a positive experience of life 50 years in.
This is just what I was thinking too!