Psychiatric medication

History

Modern psychiatric medication has advanced greatly in the past century. The reuptake hypothesis by Julius Axelrod involves the interaction among neurotransmitters, and forms the cornerstone of the development of modern psychotropic drugs. His work allowed researchers to further advance their studies into the effects of psychiatric medication. Mental health medications were first introduced in the mid-20th century with the widespread introduction of chlorpromazine, an antipsychotic. The popularity of these drugs have skyrocketed since then, with millions prescribed annually.

As of 2013, the 10 most prescribed psychiatric drugs by number of prescriptions were alprazolam, sertraline, citalopram, fluoxetine, lorazepam, trazodone, escitalopram, duloxetine, bupropion XL, and venlafaxine XR.

Administration

Psychiatric medications are prescription medications, requiring a prescription from a physician, such as a psychiatrist, or a psychiatric nurse practitioner, PMHNP, before they can be obtained. Some U.S. states and territories, following the creation of the prescriptive authority for psychologists movement, have granted prescriptive privileges to clinical psychologists who have undergone additional specialised education and training in medical psychology. In addition to the familiar dosage in pill form, psychiatric medications are evolving into more novel methods of drug delivery. New technologies include transdermal, transmucosal, inhalation, and suppository supplements.

Research

Psychopharmacology studies a wide range of substances with various types of psychoactive properties. The professional and commercial fields of pharmacology and psychopharmacology do not typically focus on psychedelic or recreational drugs, and so the majority of studies are conducted on psychiatric medication. While studies are conducted on all psychoactive drugs by both fields, psychopharmacology focuses on psychoactive and chemical interactions within the brain. Physicians who research psychiatric medications are psychopharmacologists, specialists in the field of psychopharmacology.

Adverse and withdrawal effects

Psychiatric medications carry risk for adverse effects. The occurrence of adverse effects can potentially reduce drug compliance. Some adverse effects can be treated symptomatically by using adjunct medications such as anticholinergics (antimuscarinics). Some rebound or withdrawal adverse effects, such as the possibility of a sudden or severe emergence or re-emergence of psychosis in antipsychotic withdrawal, may appear when the drugs are discontinued, or discontinued too rapidly.

Types

There are six main groups of psychiatric medications.

Antidepressants

Antidepressants are drugs used to treat clinical depression, and they are also often used for anxiety and other disorders. Most antidepressants will hinder the breakdown of serotonin or norepinephrine or both. A commonly used class of antidepressants are called selective serotonin reuptake inhibitors (SSRIs), which act on serotonin transporters in the brain to increase levels of serotonin in the synaptic cleft. SSRIs will often take 3–5 weeks to have a noticeable effect, as the regulation of receptors in the brain adapts. There are multiple classes of antidepressants which have different mechanisms of action. Another type of antidepressant is a monoamine oxidase inhibitor, which is thought to block the action of Monoamine oxidase, an enzyme that breaks down serotonin and norepinephrine. MAOIs are not used as first-line treatment due to the risk of hypertensive crisis related to the consumption of foods containing the amino acid tyramine.

Common antidepressants:

Antipsychotics

Antipsychotics are drugs used to treat various symptoms of psychosis, such as those caused by psychotic disorders or schizophrenia. Atypical antipsychotics are also used as mood stabilizers in the treatment of bipolar disorder, and they can augment the action of antidepressants in major depressive disorder. Antipsychotics are sometimes referred to as neuroleptic drugs and some antipsychotics are branded "major tranquilizers".

There are two categories of antipsychotics: typical antipsychotics and atypical antipsychotics. Most antipsychotics are available only by prescription.

Common antipsychotics:

Anxiolytics and hypnotics

Benzodiazepines are effective as hypnotics, anxiolytics, anticonvulsants, myorelaxants and amnesics. Having less proclivity for overdose and toxicity, they have widely supplanted barbiturates.

Developed in the 1950s onward, benzodiazepines were originally thought to be non-addictive at therapeutic doses, but are now known to cause withdrawal symptoms similar to barbiturates and alcohol. Benzodiazepines are generally recommended for short-term use.

Z-drugs are a group of drugs with effects generally similar to benzodiazepines, which are used in the treatment of insomnia.

Common benzodiazepines and z-drugs include:

Mood stabilizers

In 1949, the Australian John Cade discovered that lithium salts could control mania, reducing the frequency and severity of manic episodes. This introduced the now popular drug lithium carbonate to the mainstream public, as well as being the first mood stabilizer to be approved by the U.S. Food & Drug Administration. Besides lithium, several anticonvulsants and atypical antipsychotics have mood stabilizing activity. The mechanism of action of mood stabilizers is not well understood.

Common mood stabilizers:

Stimulants

A stimulant is a drug that stimulates the central nervous system, increasing arousal, attention and endurance. Stimulants are used in psychiatry to treat attention deficit-hyperactivity disorder. Because the medications can be addictive, patients with a history of drug abuse are typically monitored closely or treated with a non-stimulant.

Common stimulants: