can anyone tell me when you had an operation?

well cutting along story short my dad had 2 operations to remove fluid from he'slungs but he'sgiving off the impression that he is hallucinating and i've been told this is called post operative depression he has suffered from depression for along time as he lost 6 members of he's family in 6 months so hence the reason for the depression i feel this time round due to the op's he is suffering the depression again any one with experiance out there who can help try and give me any advice thankyou so much in advance i am calling he's gp tom to see if he will give him some different meds b/caue the ones he's taking at the mo are cleary not helping its been about 5/6 days after op any help would be appriciated thanx x