Segraves K A, Segraves R T, Schoenberg H W
Arch Sex Behav. 1987 Apr;16(2):125-37. doi: 10.1007/BF01542066.
The use of sexual symptomatology to differentiate psychogenic from organogenic impotence was studied. All patients were independently classified based on the evaluation of a minimum of one night of nocturnal penile tumescence recording, a sleep lab technician's rating of penile turgidity of erections, Doppler determination of penile blood flow, determination of serum prolactin and testosterone levels. Three aspects of symptomatology significantly discriminated the criterion groups. The single best predictor was the presence or absence of early morning erections as reported by the patient.
