Dementia patients sometimes suffer from delusions. These delusions might be harmless. The patient may think she’s eating steak, but she’s really eating some jelly. You don’t know. If you attempt to shake the dementia sufferer from her delusion, she may become violent or agitated.
The number one priority is to make sure that the patient is safe. Try to divert and distract the delusional patient that wanders and has the potential to cause harm.
Otherwise, as long as the delusions don’t go so far as to cause the patient to wander or do anything harmful, then by all means go along with it. If the dementia patient thinks she’s at work, then agree that she’s at work. If the dementia patient becomes worried about pedestrians passing by on the nearby sidewalk, close the shades and assure the patient that she’s safe and that the doors and windows are locked.
All you can do for these patients while they’re under a delusion is to make them feel safe and try not to let them get agitated. You can’t cure them. You can simply ease their fears and make their confusing days a bit more manageable.