Question
Hi.  I was wondering, is it possible for chronic pain to cause its sufferer a sort of intermittent psychosis?  My mother has been suffering from chronic pain for years, and when she runs out of her medicine, and sometimes even after she has it, she becomes very different.  Angry at everything, violent a couple times, destructive toward property, and she says really horrible things.  Afterward, if I question her about these things, she claims not to remember them.  Any insight?  Thank you.

Answer
Hi Amber,
  I found your question in our question pool and thought I may be able to help.
If your mother is taking a opiate pain medicine it is likely that when she runs out of her medicine she is experiencing withdraw symptoms from the narcotic pain medicine as well as increased, untreated pain. Withdraw symptoms can cause extreme irritability. Other symptoms include;

Early symptoms of withdrawal include:

Agitation
Anxiety
Muscle aches
Increased tearing
Insomnia
Runny nose
Sweating
Yawning

Later symptoms of withdrawal include:

Abdominal cramping
Diarrhea
Dilated pupils
Goose bumps
Nausea
Vomiting

Your mother could continue having withdraw symptoms for a time even after she has her pain medicine. It could take several doses of the medicine to get the level of medicine in her blood to it's usual level and stop the withdraw symptoms.
I do not have an explanation for her not remembering her behavior during these times as this is not generally a withdraw symptom. It is possible that she is ashamed of her behavior at these times and later claims not to remember as a way to avoid discussing her behavior.

I hope this helps. If you have any questions or need additional information please don't hesitate to ask.
     Thanks
       Tracy