Abstract: Disclosed are methods for detecting abnormalities in prolactin daily rhythms. The methods involve comparing a prolactin profile of a vertebrate (including a human) subject being tested that has been compiled over a predetermined period to a predetermined standard prolactin profile for healthy subjects. The method also involves determining whether the vertebrate subject has an abnormal daily prolactin rhythm by ascertaining whether (i) at any point during waking hours the prolactin level of the subject being tested is greater than 1 SEM above the normal prolactin profile of said healthy subjects, and/or (ii) at any point during sleeptime the prolactin level of the subject being tested is at least 1 SEM lower than the normal prolactin profile of said healthy subjects. Also provided are methods for determining adjustments needed to an abnormal prolactin profile (or daily rhythm) to cause it to conform to the prolactin profile (or rhythm) of a healthy subject, and methods for effecting such adjustments.