Shock therapy

Shock therapy is the deliberate and controlled induction of some form of physiological state of shock in an individual for the purpose of psychiatric treatment. Shock therapy attempts to produce this state artificially and under controlled conditions, on the premise that states of shock often induce improvement in the patient's mental state once the patient recovers.

Various types of shock therapy were common until the late 20th century, when many advances in available psychiatric drugs allowed more and more psychiatric conditions to be treated with a combination of medication and talk therapy. Electroconvulsive therapy, the only type of shock therapy still practised in the 21st century, is now reserved only for severe cases of depression and bipolar disorder which do not respond to other kinds of therapies.

History
Physicians have noticed for thousands of years that a person's mental state sometimes changes dramatically following recovery from physiopathological shock or brain seizures, whether induced by a head injury, an intense febrile illness such as malaria, or chemically induced loss of consciousness or convulsions. In the time of the Roman Empire, for instance, electric fish were used to provide electric shocks to ill patients. For example, Scribonius Largus used it in AD 47 for treating persistent headaches. It is said that the Emperor Claudius himself was one of his patients.

Other instances of medical use of shock therapy were Paracelsus, who used seizures induced by camphor to treat psychosis in the 16th century; Drs. Jean LeRoy (France, 1745), Robert Whytt (London, 1751) and Leonard Yealland (London, 1917), all of whom used weak (non-convulsive) faradic electrical shocks to treat various "nervous, hypochondriac, or hysteric" cases as well as men suffering "shell-shock".

With the rise of more biological explanations for mental disease at the end of the 19th century, the search for biological treatments also increased. In a short decade between the 1920s and the 1930s, several methods were discovered by scientists who started to experiment with shock-inducing techniques. Due to the absence of any other effective therapeutic approaches to mental disease, in the next two or three decades shock therapy became one of the most widely used tools of psychiatry. Hundreds of thousands of patients were subjected to it, including many important personalities, such as writers Ernest Hemingway (who shot himself after undergoing ECT treatment at the Mayo Clinic) and Janet Frame, poets Sylvia Plath (who also later committed suicide) and Robert Lowell, performer Paul Robeson, rock star Lou Reed, film actresses Frances Farmer, Vivien Leigh, Clara Bow and Gene Tierney, pianists Vladimir Horowitz and Oscar Levant, talk show host Dick Cavett and politician Thomas Eagleton.

Though popular in the first half of the 20th century, most shock therapies are now considered too risky for general use. Only electroconvulsive therapy is still used today, and it is reserved for severe forms of mental illness that do not respond to other treatments.

Forms of shock therapy

 * Malarial fever therapy involves the inocculation of malarial protozoa into the bloodstream of patients, in order to provoke episodes of intense fever and unconsciousness, which are sometimes followed by convulsions. The method was discovered by an Austrian physician Julius Wagner-Jauregg (1857-1940) in the 1910s, who got the Nobel Prize for his discovery. For a while, it was used for treating the general paresis of the insane, caused by tertiary syphilis. It is no longer used.
 * Insulin shock therapy involves injecting a patient with a large amount of insulin, which causes convulsions and coma by provoking brain hypoglycemia. It was discovered by Polish physician and researcher Manfred Sakel (1900-1957) in 1933 and was used well until the 1950s for the treatment of depression and psychosis. It is also rarely used.
 * Metrazol shock therapy involves injecting a patient with Metrazol (cardiazol), a drug that quickly induces powerful brain seizures. It was discovered by Hungarian physician and researcher Ladislas J. Meduna (1896-1964) in 1934. It was soon superseded by electroconvulsive therapy, because it was difficult to control and had many adverse effects.
 * Electroconvulsive therapy involves inducing a grand mal seizure in a patient by passing an electrical current through the brain. It was discovered by Italian researchers Ugo Cerletti (1877-1963) and Lucio Bini (1908-1964). It is still in use today, albeit with restricted indications, such as usually untreatable depression or bipolar affective disorder and obsessive-compulsive disorder or anxiety disorders. In these cases, it is considered a safe and effective procedure, when carried out under a clinical protocol which involves EEG monitoring, application of muscle blocking agents and general anesthesia or sedation.

Mechanisms of action
The exact mechanism or mechanisms by which shock therapies work is unknown. The mild effectiveness of most forms of shock therapy indicate that a generic defense mechanism might be at work, i.e., the inducement of physiological changes to an external aggression by external or internal physical and chemical agents usually mobilise the organism's mechanisms at hand to fight impending physiopathological changes in the immune, endocrine, cardiovascular, metabolic, nervous, and other, systems.

Unfortunately, when shock therapies were most used, science had no effective tools to study this hypothesis. Studies about the underlying mechanism of electroconvulsive therapy, though, still continue. Many hypotheses have been proposed, but recently a surprising solution might have been discovered: researchers unveiled that transcranial electroshock induce neoneurogenesis (i.e., the growth of new neurons) in some areas of the brain which are involved with the control of emotions and memory. Since chronic depression is associated to a neuron loss in the same areas, this might explain the therapeutic effect. Some antidepressive drugs, such as SSRI-based therapy (e.g., fluoxetine, a.k.a. Prozac), might also share the same mechanism of action.