I would think trauma, also.
I have a real interest in this topic, in June of this year I underwent Open Heart Surgery, I was under anesthesia from 715am to 530pm at least that is my recollection from the last thing I remember in the morning to when I woke up in the afternoon.
During my 5 night/6 days in Cardiac ICU, I had to be put under again for the implantation of a pacemaker.
Physically I was never really in pain, mentally was another subject, I had some extreme anxiety, emotional instability basically crying from what I thought was my impending death.
I chalked it up to lack of rest in the hospital, excessive number of drugs I was given and the anxiety of having major surgery.
Since I’ve been home, I’ve wondered did the anesthesia have some effect on my brain, leading up to the surgery I was put under for a test where ketamine was used as the main drug.