Thought, Mood and Behavior Disorders

From the outset, in its use with epileptics, side benefits of PHT were noted. Improvements in thought, mood and behavior were observed. “Salutary effects of PHT on personality, memory, mood, cooperativeness, emotional stability, amenability to discipline, etc., are also observed, sometimes independently of seizure control.”—Goodman and Gilman (1955)703

703. Goodman, L. S. and Gilman, A., The Pharmacological Basis of Therapeutics, 2nd Ed., 181-188, Macmillan, New York, 1955.


Phenytoin has been found useful for so many symptoms and disorders that an overall summary is impractical.

The section on Thought, Mood and Behavior Disorders deserves special attention—not only for the benefits in these disorders themselves, but because of the resultant lessening of  tension and stress associated with many other disorders.

Soon after phenytoin’s introduction, in 1938, reports started to appear in the medical literature of patients’ improvement in mood, concentration, cooperativeness and sense of well-being. By now, extensive published evidence form widely separated sources has established PHT’s usefulness for thought, mood and behavior disorders.

Phenytoin has been shown to have a calming effect on the overactive brain. Symptoms of this condition are preoccupation, multiple thinking, and flashes and fragments of thoughts coming and going. PHT reduces this uncontrolled activity enabling more normal thinking processes to be restored. This effect is usually achieved within an hour, without sedation.

Anger and fear and related emotion are usually found in combination with the overactive brain. Emotional states related to anger for which PHT is therapeutic are impatience,  implusiveness, irritability, aggression, hostility, rage, and violence, Emotional states related to fear for which PHT is therapeutic are worry, anxiety, guilt, pessimism and depression. Although excessive anger and fear states are decreased or eliminated by PHT, realistic reaction of anger and fear are not interfered with.

Sleep disturbances found in combination with the overactive brain fall into two general categories. The first and most frequent category is symptomatized by difficulty in falling asleep because of over-thinking, light sleep accompanied by unpleasant dreams and frequent nightmares, and insufficient sleep. A less frequent category is symptomatized by excessive, so-called avoidance sleep. Relief from both types of sleep disturbances is usually prompt with PHT.

PHT is effective with extremes of mood ranging from depression to the hyperexcitable state. These apparently disparate effects are observed in the overactive, impatient individual who is calmed by PHT, and the tired, energyless individual who has a return to normal energy levels.

Somatic symptoms frequently associated with thought, mood and behavior disorders are usually relieved by PHT within an hour. Among them are headaches, pain, stomach discomfort, dizziness, trembling, excessively cold or warm hands or feet, and shortness of breath.

Stress. When the brain becomes overactive and the emotions of fear and anger appear, the body goes on alert, and a state of vigilance develops. For short periods this can be normal. But, if this is a chronic condition, there is constant stimulation of the hypothalamic-pituitary-adrenal (HPA) axis, resulting in the release of the chemicals of fight and flight. A cycle is created, the chemicals keeping the brain overactive and the overactive brain stimulating release of the chemicals. A condition of stress develops. By correcting the overactive brain, PHT seems to break this cycle, causing a more normal state to return—and stress, commonly associated with a wide range of disorders, is diminished or eliminated.

Basic mechanism studies are consistent with the clinical observations of the effectiveness of PHT. Of particular relevance are the studies in the section, Stabilization of Bioelectrical Activity. (See Basic Mechanisms of Action) They show that PHT, without affecting normal function, corrects hyperexcitability, as in post-tetanic potentiation or post-tetanic repetitive discharge. This would seem to be the mechanism by which PHT corrects the overactive brain.