Psychopharmacology

Psychopharmacology is the use of any drug that acts upon the mind by affecting brain chemistry. Fly agaric can be regarded as the first such drug, being known from at least 10000 BCE.

Generally hallucinogenic drugs were used in hunter-gatherer societies, which can be observed until today. With the dawn of the neolithic, drugs which require a longer time for production followed, which were mainly narcotic drugs such as alcohol and opium, but also cannabis.

However the use of psychiatric drugs to restore mental health, or at least limit aberrant behaviour, has only been widely used since the 1950s when a number of new classes of drugs were discovered, notably tranquillizers and antidepressants.

Following their discovery some of these drugs gained very high popularity amongst psychiatrists and general practitioners. Some once popular drugs are now out of favor, and there are fashions in psychiatric drugs, as with any other kind of drug.

Reduction of anxiety

Barbiturates were used as hypnotics and as anxiolytics, but the development of the safer benzodiazepines (Lowell Randall and Leo Sternbach, 1957) in the 1960s and 1970s led to billions of doses being consumed annually under tradenames like Mogadon, Valium (diazepam, 1963) or Librium (chlordiazepoxide). However the problems of chronic use and dependence led to the use of other drugs, such as the azapirones.

Antipsychotic drugs

Outside of the more popular drugs there was success in the treatment of some of the symptoms of psychosis and depression. The first antipsychotic compound, for the treatment of the symptoms of schizophrenia, was chlorpromazine (known by tradenames like Largactil (Chlorpromazine hydrochloride) or Thorazine) in 1953. It when beyond simple sedation with patients showing improvements in thinking and emotional behaviour, over 100m patients were treated. From chlopromazine a number of other similar antidopaminergic compounds were developed, such as the phenothiazines. Such drugs had a revolutionary role in transforming mental institutions from a almost purely custodial role. But the limited knowledge of brain chemistry means that even more modern compounds cause a range of extrapyramidal side-effects and while effective at controlling acute symptoms are less value in chronic symptoms.

Antidepressant drugs

For depression two major classes of drugs were developed in the late 1950s, one group based on iproniazid (a MAOI developed at Hoffman-LaRoche, 1956) the other on imipramine (a tricyclic antidepressant developed by R. Kuhn at Geigy Labs in 1958). Improvements were effected but the results were less marked than with anti-psychotic drugs. Tetracyclic antidepressants or SSRIs like Prozac (discovered by D. T. Wong at Eli Lilly labs in 1974, FDA approved in 1987).

Mood stabilizers

In 1949, the Australian John Cade discovered that lithium salts could control mania, reducing the frequency and severity of manic episodes. It did not take long for others to discover that these drugs also reduced the frequency and severity of depressive episodes. Other mood stabilizers include Valproic acid and Carbamazepine.

Addictions

Research with the drug ibogaine to treat heroine addiction has shown much promise in eliminating physical withdrawal symptoms. The drug is obtained from an african plant and was used as early as the 1960's by Claudio Naranjo.