Hi and welcome to HCM.
I'm Dr. Taimur and I will be addressing your health concerns.
I have read your question and understand your concern.
Any chronic illness especially in the elderly can lead to
depression and
anxiety, as you explained the situation this is not something new. That's why anxiolytics and antidepressants are usually added to the prescription.
But the association of tea with anxiety symptoms aggravation does not seems to be true.
In my patients I usually do prescribe SSRI's ( like
fluoxetine and
paroxetine) in morning along with Benzodiazepines ( like alprazolam) at night.
After few weeks we taper the dose of benzodiazepines and continue SSRI's for 6 months of treatment.
But this should be prescribed by a
psychiatrist or an internist.
My recommendation to you is to get an appointment and get your dad properly examined and investigated.
Meanwhile you should keep him busy in activities like gardening etc or anything he like to do.
And once again forget about tea.
I hope this might be of some help, if you have any query feel free to ask me any time.
Thanks.
Dr. Taimur