How to differentiate between psychological and organic erectile dysfunction

Psychological impotence usually occurs acutely. The early morning erections and erections during REM sleep (nocturnal penile tumescence; NPT) are usually preserved. If a man repos of spontaneous erections at times when he does not plan to have an intercourse, having morning erections, or having good erections with masturbation or with paners other then his usual one, the organic causes can be considered negligible. Nocturnal penile tumescence is a normal physiological phenomenon seen in males during early morning hours. Squeeze technique is used in pre mature ejacualtion Ref: A Sho Textbook of Psychiatry, Niraj Ahuja, 7th Edition, pg. no. 128, 130 Synopsis of Psychiatry, 11e, pg 577.