Telemarketing firms do many things to try and get customers to buy, or buy into the products they are pushing. It's a common practice in North American, and given that human nature is similar everywhere, I dare say the practice is common everywhere. The fact that a person may be "T" really has no bearing on it, the person doing the calling could be suffering from any number of conditions, both mental and physical ones. I imagine that a person who believes them self to be be perfectly healthy having to say the suffered from a mental disorder would feel the same way as we might.
Steph