Analgesics are substances that relieve or prevent pain without causing unconsciousness or completely deadening the nerve centers.  Examples of conventional analgesic drugs are bromides, aspirin, morphine, opium, and belladonna.  Morphine as an example has been used extensively as a pain killer in human treatment.  One serious drawback to the use of morphine is that when used for extensive periods on a single patient, it is usually addictive.  Other drawbacks are that morphine often produces serious side effects in many patients, including interference with heart and breathing, and vomiting.  Aspirin, very effective for certain types of human pain, has limitations for most severe pain situations, and can result in undesirable side-effects. 
The method of the present invention, employing prescribed dosages of D-phenylalanine, have demonstrated in controlled tests on human patients effectiveness as a pain killer equal to or superior to morphine, with no deleterious side effects and no patient addiction. 
Treatment of manic depression, a major depressive disorder, up to the present has involved both psychological and biochemical means or combinations thereof, which have overall been unsuccessful.  Drugs that have shown some promise in some patients have often caused severe traumatic side effects, resulting in other body damage to the patient. 
Applicant has discovered that using D-phenylalanine independently in daily dosages, bipolar manic depression, depressive states, and unipolar depression can be successfully treated with no side effects to the patient.  Recovery can be accomplished over a period of days and sustained by continuous daily administration with no short or long term deleterious side effects on the patient.  Other antidepressant compositions may be used with D-phenylalanine without deleterious interaction. 
Applicant has also discovered some relationship between the treatment of manic depression and Parkinsons disease.  Parkinsons disease is a dehabilitary neurological disorder disturbing the motor function of the patient causing tremor, rigidity and other physiological symptoms.  Specifically continuous daily administrations of D-phenylalanine alone extended over a period of days has been shown to dramatically improve the patients physiological and motor abilities, effectively alleviating the traumatic effect of the disease.