Was it necessary to have a psychologist with a briefcase at my job?

I been working at my job for over 20 years and all of a sudden, my boss told pulled me in the office and had me sit down with Human Resources and there was this guy I didn’t even know who was wearing a suit and a had a briefcase and he introduced himself saying he is a psychologist with mentioning his concerns about my anger management or psychotic behavior but I never had this problem at all and always been a hard worker. I felt so uncomfortable and didn’t know what he was talking about or who he was. He kept sitting with me at my job too and watching me asking lots of questions about why I am doing the job like that and asked me about mental issues which I was not aware of. He even gave me one of those IQ tests and asked me to color in a room with having my use crayons. 

Was this necessary to have a psychologist with me at my job? HR and my boss never explained to me about this at all or what the reason for this was. I thought it was weird.