I know it’s fiction, but it is, as you say later, a reflection of the people who wrote and produced it.
Since they are likely in the same age range as those who are actually committing suicide, does that not strike you as more than coincidence?
Sometimes cultural shifts can be seen in the art developed by a culture years before it becomes evident in the lives of the people in the culture. Look at the poetry, art and music of the 50s and see how the 60s turned out.
I see your point, although I don’t know the age of the writers of “Desperate Housewives.”
We also can’t tell much about the actual numbers of suicides. A rate of increase gives us no information about magnitude: from 1 to 2 is a 100% increase.
Just using a common-sense filter, my prediction would be that the majority of the increase is in divorced or widowed individuals between 60-64, perhaps with severe health issues. This is the same group most likely to commit suicide when they’re in their 70’s or 80’s.
As Mr. Hawk pointed out, the increased use of psychotropic drugs is another likely factor.