Does my father have a delusional disorder?

I was unable to find any section in the forum discussing delusional disorders.
I am a medical student in my final year and I think my father has a delusional disorder that I dont know how to deal with. My parents were divorced since i was 4 so I barely recall how their relationship was. I've lived with my mother all these years and only visited my father on weekends or holidays. He is not educated, he quit school by the 8th grade and retired by the late 40s! He is 54 years old now. I saw him once in his car driving, I was in another car and he was covering his face with a scarf so that no one could identify him! He lives with my grandparents (which is accepted in my culture) but everytime he gets out of his room he locks the door and hides the key away. He always says wierd things about people wanting to kill him. I can't get the complete story right because he tries to look normal whenever I visit. But I hear alot from my aunts -his sisters- and my grandparents. My mother mentioned that when they were together he refused to eat from what she cooked until she did first just in case she poisoned the food in order to kill him!! He also never owned a mobile phone and refuses to use it if we bought it for him, he does not want people to call him and find where he is at any time. Other than that he seems fine (or so I guess).
I dont know what makes him paranoid. I think his symptoms are worsening with time. What worries me too is that my aunt -his sister- has developed an Obsessive compulsive disorder in the last several years; where she keeps washing the bathroom and herself all the time until she developed skin reactions in her hands from the excessive use of soap.
She refuses seeing a doctor or even talking to him over the phone, and I understand how such a disorder needs behavioral therapy which itself might not even work for her.

[Roger Gould, M.D.]

You are definetly describing a chronic paranoid condition that has been stable and now may be deteriorating...that, and your aunt's condition, are not something that you inherit....so not to worry, as long as you maintain a healthy lifestyle.   There are no short cuts to treatment if the person will not see a doctor and get treated..there are treatments for both of these conditions.

[inspiration]

Is my family going crazy? and am I now at high risk of developing one of these psychiatric illnesses?
Or are they normal and I'm seeing things that doesn't exist (& we tend to do that as med-students!)
Please reply,, am worried.. I need to help my father but I dont know how.

[Jaquta]

Most families have elements of dysfunction.
Having family members with certain psych disorders can increase another family members risk.  I would think your risk would be quite low though.  
They don't sound without issues.  If they don't have every other disease or disorder you've studied then I would say it's probably not a med-student thing.
I think there may be some things you fear that you may see in others that concerns you and causes you anxiety.

I can't say whether you, or your family, are seeing things that aren't there.  If you have concerns about an interpretation then you can ask the person to perhaps help clarify and put into context the behavior you saw.

The poisoning food comment reminded me of a doctors interpretation of my behavior around food.  While he thought I thought people were trying to poison me it was more about issues I have with food and weight.  If he had of been sufficiently skilled and had of asked questions he may have been able to make a better interpretation.

Sorry!  I digress.

Some elements of your father's behavior seem as though they could be explained by others reasons (locking his room for privacy -although may indicate a lack of trust).
The scarf incident may just be a perceptual thing and there may be a rational explanation.

Combined, everything does sound a little concerning.
Paranoia can be caused by a number of different disorders (depression, schizophrenia, etc).  It can equally be caused by stressed.  Maybe early onset neuro-degenerative conditions could be responsible?  I don't know.

The doctor usually offers great insights and advice.  I would recommend following his advice.

Good luck for your final year of med school.

[inspiration]

Thank you for your reply
about the poisonning, am pretty sure because he said it clearly.
About the privacy, am not sure, he would allow me to stay in his room for hours reading a book or something but would not worry, even if he left the house during that time. I really dont know but when you look at the whole picture it really makes you think of him as being paranoid.
He could be having an ongoing depression as you related it to delusions as he has no interest in any activities with many other depressive criteria that he fits in.
I hhope he gets better, or atleast realizes that what he does is abnormal.

[inspiration]

Dear Dr.,
Thank you for your feedback, am not sure that we have efficient psychotherapy in my country, they mainly rely on drugs, other than the wrong perception wide spread about psychiatric illnesses.

If there are ways that I can convince him about his false fixed ideation I would be greatful if you can share them with me..

Best regards

[Jaquta]

It sounds unlikely that he would realize his behavior is abnormal.  Sometimes it takes someone to point out to us our eccentricities, etc.  It's possible he may have some awareness of it but not understand it.

In truth most countries over-rely on medication.  Far cheaper than investing in a persons long-term health and well-being (through therapy).
Most countries also still attach stigma to a psychiatric illness (and also to some physical ones too).

I think I have seen written previously to assert reality (this is the behavior, this is what you're doing).  People have mentioned having open, honest discussions with the person.  Perhaps mention your concerns.  Don't frighten him though.  Have you asked him to visit the doctor?

I can't understand why they wouldn't treat their illnesses if it would make such a huge difference to their quality of life.

In medical school what did they teach you about this?  Perhaps you could try and apply some of what you were taught to this situation.  You probably don't need to convince him about his false beliefs, just convince him to see a doctor.

Good luck.  I hope he gets better too.