If your pineal gland does not produce adequate melatonin early enough in the evening, it is difficult to go to sleep. If secretion does not continue, you may wake up too soon. If your pineal gland secretes too much or for too long into the next day, you will have a tendency to be sleepy and not rested the next morning. Continuing melatonin production into the day can also result in depression and tiredness. If you do not get adequate sleep, mental acuity decreases too. Insomnia exists when melatonin levels are low or when it is produced at the wrong time. Supplementing can help reestablish balance and help you set your biological clock naturally.
Melatonin stabilizes electrical activity of the central nervous system. The pineal, primarily through melatonin, acts as a synchronizing and stabilizing organ. Nighttime melatonin levels are low in people with major depressive and panic disorders. Individuals with noticeable mood swings or are melancholy also have depressed melatonin levels. Both seasonal affective disorder and non-seasonal cyclic depressions are related to the peaks and valleys of melatonin levels.
Stress and/or dietary lack of tryptophan may make deficiencies of melatonin common. Older individuals have a reduced ability to produce melatonin. The relationships of endocrine rhythms, mood, sleep and the biological effects of light are complex. Since melatonin secretion declines with age, many researchers believe that it may help prevent age-related and free radical mediated brain damage. The melatonin corticoid relationship has significance since chronic hypercortisolemia has been associated with age related deterioration of the brain (including Alzheimer's disease), glucose intolerance, arteriosclerosis, impaired immune function and cancer. Melatonin appears to mediate the entire aging process.