Stephen Lett (4 April 1847 – 11 October 1905) was born in Ireland but raised and educated in Canada.
He became a physician and was the superintendent of an asylum.
He was also a well known medical writer.
Lett became well known as the author of “The relationship of insanity to masturbation,” which was published in (1886–87) and a variety of articles concerning addiction.
The most important of these appears to be the “Treatment of the opium neurosis”.