parent with Parkinsons having panic/anxiety attacks

My Father who is 80 and has Parkinsons Disease (reasonably early stages) is suffering from anxiety which he describes as panic attacks. These feelings occur when he has to do anything or go anywhere without his wife (whom he relies on totally). However, he gets himself into a real state even if they are planning on doing anything together such us taking a long car journey. He refuses to go away on holiday and only really feels secure at home.
Does anyone have parents/family suffering with this and do you know of anything (books/tapes etc) that helps ? I realise that these feelings may be as a result of changes in the brain as a direct result of Parkinsons so may therefore differ in non-drug related treatment. Hope this all makes sense !