If you know someone with chronic pain or disease, chances are they are also suffering from depression. Depression tends to be co-morbid when it comes to chronic illnesses.
I speak from experience, both my own and in my family, when I say we need our friends, family, and neighbors. When battling with two or more very difficult conditions, we tend to become hermits. This can feed the depression, which feeds the pain, which feeds the depression.
As you can see, it’s a vicious cycle; it needs to be broken. While not impossible, it is very difficult to fix alone. This is where you come in. It may take some gentle persuasion, but offer to help with something. Even if it’s only going out for coffee, you will be doing good.