psychopharmacology , in its broadest sense, the study of all pharmacological agents that affect mental and emotional functions. The term is usually applied more specifically to the study and synthesis of drugs used in the control of psychiatric illnesses, namely the antipsychotic, antianxiety, antidepressant, and antimanic medications. The widespread use of drugs among individuals suffering from mental illness is a relatively recent phenomenon, developing since the 1950s.

Antipsychotic Drugs

Antipsychotic drugs can ameliorate the types of delusions and hallucinations characteristic of bipolar disorder (see depression ) and schizophrenia . The first drug of this type was reserpine , whose use dates from ancient Hindu medicine but whose reintroduction as an antipsychotic agent in 1954 marked the beginning of the large-scale use of antipsychotic drugs. Because of side effects, including depression, reserpine has been supplanted by phenothiazine drugs. The phenothiazine chlorpromazine (Thorazine) was the first to be widely applied to mental disorders and remains one of the standard drugs. Drugs of the phenothiazine family are most useful in the treatment of schizophrenia. They are thought to act in part by blocking dopamine receptors at the synapse, reducing brain activity. The phenothiazines and clozapine have been credited with a revolutionary transformation of mental health care, enabling increasing numbers of psychotic persons to function outside the hospital. Antipsychotic drugs may have negative side effects, such as the dulling of physical and mental functioning, tardive dyskinesia, and sedation.

Antianxiety Drugs

Antianxiety drugs , including the propanediol meprobamate (Miltown or Equanil), and the more recent benzodiazephines—such as diazepam (Valium)—have found wide use in reducing tension and anxiety among individuals with less serious mental disorders, but may lead to addiction if abused. Although they form a chemically diverse group, the physiological effects of each are similar; in small doses they relieve anxiety by reducing muscular tension, and in larger doses they produce sedation, sleep, and anesthesia (see depressant ). Antianxiety drugs are the most frequently prescribed pharmaceuticals in the United States.

Antidepressants

Antidepressants appeared in the late 1950s, and have been used in the treatment of individuals suffering from major depression or the depression phase of bipolar disorder. Antidepressants include the tricyclics and monoamine oxidase (MAO) inhibitors. These drugs have the effect of increasing the concentration in the nervous system of catecholamines such as epinephrine . The toxic effects of the MAO inhibitors have been largely overcome in recent years, and the drugs are still used in many instances. They have been supplanted in many uses, however, by tricyclic compounds, such as amitriptyline (Elavil), and the newer serotonin increasers, such as fluoxetine (Prozac) and sertraline HCL (Zoloft). Tricyclics are chemically similar to phenothiazines, but that activate rather than tranquilize (see stimulant ). The choice of an antidepressant often has more to do with its side effects than efficacy.

Antimanic and Hallucinogenic Drugs

The element lithium , in the form lithium carbonate, has been widely used as an antimanic in cases of bipolar disorder (manic-depression), particularly to control manic episodes. Lithium alters the transport of sodium ions in nerve and muscle cells and affects the metabolism of catecholamines; the exact mechanism of action is unknown. The hallucinogenic drugs , such as mescaline and LSD , have been of research interest because they often mimic natural psychotic states.

Psychopharmacology

Psychopharmacology

How Do Psychiatric Medications Work?

What Are the Beneficial Effects of Psychiatric Medications?

What Are the Adverse Effects of Psychiatric Medications?

What Is Next in Psychopharmacology?

Resources

Medications for mental, emotional, behavioral, and mood disorders are prescribed by medical doctors called psychiatrists, often as part of a treatment plan that includes psychotherapy (talk therapy)

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Psychopharmacology

Psychopharmacology (SY-koe-far-ma-KOL-o-jee) is the study of how medications affect moods, thoughts, and feelings. Psychopharmacology is an exciting new science. When our grandparents were young, there were no medications that helped people with attention deficit hyperactivity disorder concentrate at school or work, no medications that helped people with schizophrenia quiet the voices in their heads, and no medications that helped people with depression find the energy to face a new day. Today there are prescription medications for these disorders and many others.

Psychiatric medications generally are classified into categories that reflect the chemistry of how they work in the body (mechanisms of action) or the symptoms they help relieve. Many medications fall into more than one category. For example, the same medication might improve symptoms of both depression and anxiety. These are some major types of psychiatric medications:

• antidepressant medications, which include tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), and selective serotonin reuptake inhibitors (SSRIs)
• antianxiety medications (tranquilizers), which include barbiturates, benzodiazepines, and the atypical anxiolytic buspirone
• antimanic medications (mood stabilizers)
• anticonvulsant medications
• antipsychotic medications (neuroleptics)
• stimulants.

Physicians’ Desk Reference (PDR)

Psychiatrists and psychopharmacologists study the research about medications before prescribing them. They attend training sessions, read medical journals, and review descriptions in the Physicians’ Desk Reference (PDR) medical directory for details about how specific medications work (mechanisms), how they help patients (beneficial effects), whether they cause side effects (adverse effects), and whether they can be used safely with a patient’s regular diet and other prescription medications (drug interactions).

The PDR lists medications by generic name (fluoxetine, for example) and also by the trade name given to a particular medication by the company that sells it (Prozac, in this case). Important psychiatric medications include:

Antidepressants

• amoxapine (Asendin)
• bupropion (Wellbutrin)
• clomipramine (Anafranil)
• doxepin (Sinequan or Adapin)
• maprotiline (Ludiomil)
• mirtazapine (Remeron)
• nefazodone (Serzone)
• trazodone (Desyrel)
• venlafaxine (Effexor)

Antidepressants/Tricyclics (TCAs)

• amitriptyline (Elavil)
• desipramine (Norpramin, Pertofrane)
• imipramine (Tofranil)
• nortriptyline (Pamelor, Aventyl)

Antidepressants/Monoamine Oxidase Inhibitors (MAOIs)

• isocarboxazid (Marplan)
• phenelzine (Nardil)
• tranylcypromine (Parnate)

Antidepressants/Selective Serotonin Reuptake Inhibitors (SSRIs)

• citalopram (Celexa)
• fluoxetine (Prozac)
• fluvoxamine (Luvox)
• paroxetine (Paxil)
• sertraline (Zoloft)

Antianxiety Medications (Anxiolytics, Minor Tranquilizers)

• alprazolam (Xanax)
• buspirone (BuSpar)
• chlordiazepoxide (Librium, Librax, Libritabs)
• clorazepate (Tranxene, Azene)
• diazepam (Valium)
• halazepam (Paxipam)
• lorazepam (Ativan)
• oxazepam (Serax)
• prazepam (Centrax)

Antimanic Medications (Mood Stabilizers)

• carbamazepine (Tegretol)
• divalproex sodium (Depakote)
• lithium carbonate (Eskalith, Lithane, Lithobid)
• lithium citrate (Cibalith-S)

Anticonvulsants

• carbamazepine (Tegretol)
• clonazepam (Klonopin)
• divalproex sodium (Depakote)
• gabapentin (Neurontin)
• lamotrigine (Lamictil)
• oxcarbazepine (Trileptal)
• topiramate (Topamax)
• valproic acid (Depakene)

Antipsychotic Medications

• chlorpromazine (Thorazine)
• chlorprothixene (Taractan)
• clozapine (Clozaril)
• fluphenazine (Prolixin, Permitil)
• haloperidol (Haldol)
• loxapine (Loxitane, Daxolin)
• mesoridazine (Serentil)
• molindone (Moban, Lidone)
• olanzapine (Zyprexa)
• perphenazine (Trilafon)
• pimozide (Orap)
• quetiapine (Seroquel)
• risperidone (Risperdal)
• thioridazine (Mellaril)
• thiothixene (Navane)
• trifluoperazine (Stelazine)
• triflupromazine (Vesprin)
• ziprasidone (Geodone)

Stimulants

• dextroamphetamine (Adderall, Dexedrine)
• methylphenidate (Concerta, Ritalin)
• pemoline (Cylert)
• mixed amphetamine salts (Adderall)

Examples of well-known psychiatric medications include Prozac and Paxil (antidepressants); Valium, Xanax, and BuSpar (antianxiety medications); lithium (antimanic medication); Tegretol and phenobarbital (anticonvulsants); Thorazine and Haldol (antipsychotics); and Ritalin and Concerta (stimulants).

How Do Psychiatric Medications Work?

Psychiatric medications target the complex chemistry of neurons and neurotransmitters in the brain and central nervous system. Neurotransmitters such as serotonin (ser-o-TONE-in) and dopamine (DOPE-ameen) are manufactured in neurons (nerve cells) to carry messages from cell to cell, crossing the synaptic gap between the axon (transmitting terminal) of one neuron to the dendrites (receiving terminals) of the next neuron. The chemical structure of each neurotransmitter is designed to fit its neuroreceptor the way a key fits a lock. A change in a neurotransmitter’s chemical structure, or an imbalance at any point in this complex process, may affect emotions, moods, thoughts, behaviors, and mental states. Psychiatric medications help restore proper balance. Important neurotransmitters include serotonin, dopamine, epinephrine, norepinephrine (monoamines), acetylcholine, gamma-aminobutyric acid (GABA), glutamic acid, enkephalins, and endorphins.

What Are the Beneficial Effects of Psychiatric Medications?

Psychiatric medications can help improve many of the most distressing symptoms of mental, emotional, and mood disorders. They can reduce the stress of living with chronic diseases and conditions, and they can improve the effectiveness of counseling and psychotherapy. Among their most beneficial effects are:

• decreasing feelings of hopelessness, darkness, and apathy in depression
• preventing relapse of depression
• reducing cravings, anxiety, obsessions, compulsions, and phobias
• preventing panic attacks
• reducing hallucinations, delusions, inappropriate behaviors, and the voices that often accompany schizophrenia
• calming impulsivity, hyperactivity, and mania
• improving concentration, memory, and sleep.

Selecting the right medication and the right dosage are complicated tasks, requiring that doctors take detailed medical histories from their patients and their patients’ families. Doctors must know about other medical conditions the patient may have, about other medications the patient may be taking (including aspirin, alcohol, herbal supplements, and tobacco), and about the patient’s diet and daily life. Doctors also must monitor patients who are taking medications to ensure that symptoms improve and to adjust dosages or change prescriptions if side effects occur.

Psychiatric medications can help correct imbalances in the neurotransmitters that affect mood and behavior. Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac), fit into the serotonin neuroreceptors on neuron dendrites. This blocks serotonin from entering the neuron and keeps it active for longer periods of time in the synaptic gaps between transmitting and receiving neurons. Serotonin (5-Hydroxytryptamine) is a calming neurotransmitter that is manufactured in nerve cells from the amino acid tryptophan. Turkey is one good source of tryptophan, which may help explain why people often feel relaxed and sleepy after Thanksgiving dinner.

What Are the Adverse Effects of Psychiatric Medications?

Adverse effects are unwanted side effects, and psychiatric medications can have serious adverse effects if not monitored carefully by a doctor. Depending on the medication, adverse effects may include:

Methylphenidate (Concerta, Ritalin) is a stimulant. It often is prescribed to treat the symptoms of attention deficit hyperactivity disorder (ADHD). When misused, however, methylphenidate can harm the body in the same manner as other forms of amphetamine abuse. Photo Researchers, Inc.

• drowsiness or sleepiness at the wrong time of day, making it dangerous to operate machinery or drive a car
• restlessness or wakefulness at night
• headache, dizziness, or blurry vision
• dry mouth or increased thirst
• high blood pressure
• skin rashes
• nausea or vomiting
• unwanted weight loss or unwanted weight gain
• unwanted changes in thoughts or behavior, such as losing interest in dating, losing interest in creativity, or having suicidal thoughts that never occurred before
• seizures, especially if a medication interacts with certain foods or other medications
• muscle spasms, slurred speech, or a movement disorder called tardive dyskinesia.

The complex chemistry of psychiatric medications and the central nervous system also can affect other body organs and systems, such as the blood, bone marrow, thyroid gland, liver, and kidneys. MAOIs can interact with cheeses, wines, or cold medications to cause seizures. Some medications can interfere with a child’s normal growth and development. Others can pose serious risks to pregnant women, nursing mothers, and their babies. Older adults who are taking multiple prescriptions are at particular risk for harmful drug interactions. Some psychiatric medications also can lead to addiction, withdrawal symptoms if the medication is stopped, and accidental overdoses. People who use psychiatric medications must see their doctors regularly and report side effects as soon as they notice them.

What Is Next in Psychopharmacology?

The science of psychopharmacology is less than 50 years old, and discoveries are still being made at a rapid pace. Researchers are developing new medications that target more than one neurotransmitter at the same time, which means that they can improve symptoms in multiple categories at once. Also in development and clinical trials are newer medications with fewer adverse effects, reduced risk of addiction and withdrawal symptoms, and less chance for tardive dyskinesia.

Psychiatric medications are most effective when the people who take them work with psychiatrists and medical doctors to update their prescriptions as often as necessary.

Tardive Dyskinesia

Tardive dyskinesia (TAR-div DIS-kuhNEE-zhuh) is one of the most distressing adverse effects of antipsychotic medication. It is a disorder of the neuromuscular system that causes muscle spasms and tics, which are involuntary movements affecting the eyes, tongue, face, neck, fingers, arms, toes, or legs. Tardive dyskinesia may disappear if the medication is stopped, but sometimes it becomes a chronic condition. People who develop tardive dyskinesia often continue taking their medication because the beneficial effects outweigh this very serious adverse effect.

See also

Anxiety and Anxiety Disorders

Attention Deficit Hyperactivity Disorder

Bipolar Disorder

Brain Chemistry (Neurochemistry)

Depression

Obsessive-Compulsive Disorder

Psychosis

Schizophrenia

Tourette Syndrome

Resources

Organizations

American Academy of Child and Adolescent Psychiatry, 3615 Wisconsin Avenue Northwest, Washington, DC 20016-3007. This professional organization for psychiatrists provides information about medications for children and teenagers. Telephone 202-966-7300 http://www.aacap.org

American Psychiatric Association, 1400 K Street Northwest, Washington, DC 20005. The leading professional organization for psychiatrists in the United States offers expert information about medications. Telephone 888-357-7924 http://www.psych.org

U.S. Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20857-0001. This government agency provides the latest information on new drugs and sound advice about the proper use of medications. Telephone 888-463-6332 http://www.fda.gov

U.S. National Institute of Mental Health, 6001 Executive Boulevard, Room 8184, MSC 9663, Bethesda, MD 20892-9663. This government institute publishes an informative booklet for families called Medications (publication 95-3929), which also can be downloaded from its website in PDF format. It also posts many other fact sheets at its website offering safe and reliable information. Telephone 301-443-4513 http://www.nimh.nih.gov

psychopharmacology Study of how drugs affect behaviour. Drugs are classified according to their effect: sedative hypnotics, such as barbiturates; stimulants, such as amphetamines; opiate narcotics, such as heroin; and psychedelics and hallucinogens, such as LSD.

psychopharmacology (sy-koh-farm-ă-kol-ŏji) n. the study of the effects of drugs on mental processes and behaviour, particularly psychotropic drugs.