I am very sorry to hear of the situation. You are right, there is no correlation. Unfortunately the general population often has next to know knowledge of mental health problems and it is not uncommon for people to think that any mental health problem means a person is 'crazy'. Neither Depression or PTSD include reduced credibility a symptom. Is it possible they are speaking in a legal sense? That is, they are talking bout what will happen in court as opposed to clinically or scientifically?
You are more than welcome. If you have received a formal Psychiatric assessment & diagnosis of Depression & PTSD then there would be no reason to suspect psychotic symptoms unless there had been a change in your psychological status. A new assessment would quickly be able to confirm whether there was an emergence of psychotic symptoms.
There certainly does need to be far more education!
I hope this has been of some help. Please let me know if you have further questions or would like me to clarify any part of my answer.