Harold Dearden (13 December 1882 – 6 July 1962) was a British psychiatrist and screenwriter.

Dearden was born in Bolton, Lancashire. He was educated at Gonville and Caius College, Cambridge and London Hospital. He qualified as a physician in 1911.^[1]

During World War I, he joined the Royal Army Medical Corps. He was a medical officer for the 3rd Battalion of the Grenadier Guards. In 1916, he became honorary Captain. At the Battle of the Somme he was wounded, suffering from a lost eye and shell shock. He was later invalided out of the war.^[1][2][3]

During World War II, Dearden worked as a psychiatrist and was principal interrogator at Camp 020.^[3]

He wrote the play Interference (with Roland Pertwee). He also wrote the Two White Arms which became a successful film.^[1] In 1943, he married Ann Verity Gibson Watt, they had four children.^[2]

He died at his home in Hay-on-Wye from cerebral thrombosis.^[1]

Dearden was skeptical of claims of psychical phenomena and spiritualism. In his book Devilish But True: The Doctor Looks at Spiritualism (1936), he compared cases of witchcraft to spiritualist mediums. He noted the similarity of hysterical behaviour and hallucinations.^[4]

In 1927, he wrote an article How Spiritualists are Deluded.^[5] Dearden attended séances and was a judge for a group formed by the Sunday Chronicle to investigate the materialization medium Harold Evans. During a séance Evans was exposed as a fraud. He was caught masquerading as a spirit, in a white nightshirt.^[6]

• Insanity: Prevention or Cure? (1922)
• The Moral Imbecile (1922)
• The Technique of Living (1924)
• The Doctor Looks at Life (1924)
• The Science of Happiness (1925)
• Exercise and the Will: With a Chapter on Obesity (1927)
• How Spiritualists are Deluded (1927)
• Medicine and Duty: The First World War Diary of Dr Harold Dearden (1928, 2014)
• Two White Arms: A Comedy-Farce in Three Acts (1928)
• The Mind of the Murderer (1930)
• Such Women are Dangerous (1933)
• The Fire Raisers: The Story of Leopold Harris and His Gang (1934)
• A Confessor of Women (1934)
• Queer People (1935)
• Devilish But True: The Doctor Looks at Spiritualism (1936)
• The Wind of Circumstance (1938)^[7]
• Time and Chance (1940)^[8]
• Creation's Heir (1947)
• Some Cases of Sir Bernard Spilsbury and Others: Death Under the Microscope (1948)