As said above, lol, very interesting topic, Bob!
1. Can we (and/or did you) observe differences in attitudes, behaviors and reactions of depressed people, depending if they are gay or straight?
I don't really think it depends on being gay or straight, I think it depends more on the person being extrovert or introvert. Extrovert people will be more likely to express their depressed state in public, while introvert will try to hide it from the world.
2. Are gay people psychically and/or physically (in average) less resistant to the stress which leads to a clinical depression than straight people?
I agree with the above posters, lol. Since depression is mostly caused by stress (according to me), it really depends on how much stress that person receives on a daily basis. The sad part is of course that (closeted) gay people are more likely to endure more stress than straight people.
3. Is it easier (or in contrary more difficult) to accompany, assist or help gay depressed people then straights ones?
Here I agree with Kevin though. However you react to help from others really depends on the person trying it and the place and the certain mood you're in at that moment. If I were depressed, and someone I hardly know would try to help me in the middle of a mall, I would probably resist that help. Even when I would be at home, and a really close friend would try to help me, it would still depend on my mood. Depressions don't feel as bad all the time, I think sometimes you feel a little better than other days, and that's when a person who wants to help you has to try it. (I do feel this is confusing to read lol. My apologies for that )
"Can they cope better? As a general rule, if someone is exposed to small doses of something, they can build up an immunity to it (this is the principle behind vaccinations). Because gay people suffer more society pressures that straight people, as a general rule, they have the opportunity to strengthen their internal defenses against those pressures. This will aid them if they become clinically depressed. However, it is by no means universal. Some people don't learn to cope with the smaller pressures and so they don't build up their 'immunity'." ~Graeme
I really like how you picture this, Graeme.