There is no reason why Doctor Ronny wouldn’t find Trump to be in good health. He doesn’t drink, he doesn’t smoke and he doesn’t take drugs. Also, as we know, he gets his exercise on the golf course. Maybe he should use his health as an excuse to play golf so often. High cholesterol is common in older people, yet we have to remember that high blood pressure and cholesterol are the main cause of heart attack. I think his high cholesterol may be effected by the carbs and calories that he gets from fast food.
The cognitive screening test or worksheet is not that comprehensive but it does give a doctor a good idea of whether the patient is showing signs of cognition problems. Mental disorders are a whole different ball game. A majority of people who suffer mental disorders would be deemed healthy except when self-treatment is involved (alcohol, pills etc.) Certain health deficiencies can also be caused by the symptoms of a mental illness. Insomnia, diet, lack of engagement (motivation), even grooming can pose some significant health problems.
Below is an example (and link for full size image) of a standard mental health screening form. The form covers basic identifiers that can tip off say a psychiatrist to any possible mental health issues. When you look at the form you will notice that it is filled out by the patient. I guess a person can answer the questions any way that they want.
It is possible that President Trump does not suffer from any traditional mental condition. It is quite possible that his odd behavior could be a result of the culture he grew up in.