Method for treating patients suffering from drug dependencies which lead to plasma melationin deficiencies

DETAILED DESCRIPTION OF THE INVENTION Applicant has found that persons who have become dependent upon, tolerant of, or addicted to benzodiazepines typically also suffer from an endogenous melatonin deficiency or distortion in comparison to a person with a normal endogenous plasma melatonin profile.
A deficiency in endogenous melatonin production typically comprises the production of less than about 12 .
mu.
g melatonin per night or less than 1.
5 .
mu.
g per hour during at least two hours during the night.
A distortion of a person's endogenous melatonin profile occurs when peak melatonin production occurs during the daytime, prior to 2 hours after dusk or later than about 2 hours before dawn, or when daytime melatonin production is greater than a rate of 0.
1 .
mu.
g/hour, or a combination of the foregoing.
Surprisingly, it has been found that administering melatonin to such a person in an amount sufficient to increase the amount of melatonin in the person's plasma at night to a substantially normal level for at least 4 hours of the night and, in one embodiment, to substantially simulate a normal melatonin night-time profile, can enable the person to overcome his or her dependence upon, tolerance of, or addiction to the benzodiazepine.
Preferably, the melatonin is administered in an amount sufficient to increase the amount of melatonin in the person's plasma to normal levels.
By "substantially simulate" a normal profile is meant achieving minimal blood levels of about 60 to about 200 picograms melatonin per milliliter plasma, preferably about 100 to about 200 picograms melatonin per milliliter, and most preferably about 150 picograms melatonin per milliliter, for a period of at least 4 hours during the night.
Maximal blood melatonin levels in a person with a normal melatonin profile typically are about 60 .
+-.
20 .
mu.
g/ml, as shown in FIG.
1.
The figure shows average melatonin levels throughout the body; it has been found that the melatonin level in those blood vessels which are close to the brain can be significantly higher than in peripheral veins