Unlike conventional antidepressants which are used to elevate concentrations of the neurotransmitters serotonin, dopamine, or noradrenaline ketamine influences the glutamate system. Glutamate, the major excitatory neurotransmitter, plays a central role in mediating nearly all forms of brain function, including learning, memory, cognition, and emotion.

Unfortunately, research on ketamine addicts and those who take it in large doses as a party drug has revealed that its use may lead to learning and perception problems, as well as memory disorders. Another concern is that ketamine s benefits may be relatively fleeting.

According to this view, the altered state of consciousness produced by ketamine particularly the dissolution of the self s boundaries and the experience of union with the world might constitute a profound and meaningful experience for a patient. Integrating this experience into the psychotherapeutic process might facilitate subsequent behavioral changes.

In the first controlled study, researchers reported a 50 decline in symptoms of depression within two hours of a ketamine infusion, and one third of patients were virtually symptom free within a day. Moreover, patients reported diminished thoughts of suicide a mere 40 minutes after receiving an intravenous infusion of the drug.

Recognizing that a number of drugs and precursors not controlled under the international drug control treaties have emerged in recent years in several regions throughout the world, as evidenced by the recent phenomenon of ketamine abuse in East and South East Asia referred to in the report of the International Narcotics Control Board for 2004,

Ketamine a drug primarily used as an anesthetic in veterinary medicine and as a short term anesthetic and analgesic in hospitals during surgery or other painful procedures is currently the rising star of depression research. It appears to ease depression s most severe symptoms within minutes or hours, even in patients who have a dismal track record with other treatments.

In fact, ketamine s future as a therapy for depression would be uncertain even if its efficacy were more strongly established. Because ketamine has been available for decades, there is no patent for it, so pharmaceutical companies have little financial incentive to carry out research on the drug and seek approval for its use as an antidepressant.