What do you think is wrong with my mum?

She is getting palpitations, feels weak, minimal appetite, minimal concentration, tired, lethargic, tremors in hands and dizzy. She is on Citalopram for depression and Zopiclone to help her sleep both of which have side-effects as do all tablets. She had a CT scan on her head which was normal so that rules out brain tumours. The psychiatrist and psychiatric nurses etc say she is making progress as she is starting to eat small bits and go for shortish walks with them but my mum is not convinced she is making any improvement.