Psychiatrist

A psychiatrist was a physician that diagnosed and treated mental disorders in sentient lifeforms.

Sabalom Glitz tried to kill his prison psychiatrist, after which the psychiatrist diagnosed Glitz as having a "deep-rooted maladjustment". (TV: The Mysterious Planet)

Freya Gabriel was a psychiatrist who used hypnotic regression therapy on CP Doveday, to find out his true origin. She placed the Seventh Doctor in a straight jacket, so she could question him. (AUDIO: Lurkers at Sunlight's Edge)

In the early 20th century London, Major Aske claimed to be Edward Repple's psychiatrist. (PROSE: The Clockwise Man)

Amy Pond saw four psychiatrists throughout her childhood, following her first encounter with her "raggedy man" in 1996, whom they tried to convince Amy wasn't real, which resulted in her biting them. (TV: The Eleventh Hour) They alternated so frequently that Amy stopped bothering to learn their names. Indeed, she referred to one of them as "psychiatrist number three". (PROSE: The Girl Who Tore Through the Universe)

In the Royal Hope Hospital, after the Tenth Doctor (disguised as a patient) related his adventures with Benjamin Franklin, Mr Stoker recommended a visit from the psychiatrist. (TV: Smith and Jones) The same incarnation of the Doctor later commented "…Psychiatrist's field day." when looking back on the significance of the Master's choice of a new name. (TV: The Sound of Drums)

The Zygon Kritakh forgot his true identity and began to believe he was the human he was impersonating, Michael Kirkwood. In the early 21st century, he went to see a psychiatrist to help him with his dreams of being a Zygon. (HOMEVID: Zygon: When Being You Just Isn't Enough)

Dr Gemma Corwyn acted as the Wheel's medical officer and psychiatrist. (PROSE: The Wheel in Space)

Parallel universe
Christine was a psychiatrist who attempted to treat a young Amelia Pond's belief in celestial objects other than the sun. In that alternate timeline, the explosion of the TARDIS had destroyed all the stars in the universe. (TV: The Big Bang)