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Psychoactive Drugs

Overview and use, Side effects, Precautions

Medications used to treat mental illness and brain disorders.

Overview and use

The role of psychoactive drugs, also called psychotherapeutic agents or psychotropic drugs, in the treatment of mental illness is dependent on the disorder for which they are prescribed. In cases where mental illness is considered biological in nature, such as with a diagnosis of bipolar disorder or schizophrenia, pharmaceutical therapy with psychotherapeutic drugs is recommended as a primary method of treatment. In other cases, such as in personality disorder or dissociative disorder, psychoactive medications are usually considered a secondary, companion treatment (or adjunct) to a type of psychotherapy, such as cognitive-behavioral therapy. In these situations, medication is used to provide temporary symptom relief while the patient works on the issues leading to his illness with a therapist or other mental health professional.

Psychoactive drugs can be classified into seven major categories. These include:

  • Antianxiety agents. Drugs used to treat anxiety disorders and symptoms. These include benzodiazepines such as alprazolam (Xanax), lorazepam (Ativan), diazepam (Valium), and chlordiazepoxide (Librium), and other medications including buspirone (Bu Spar) and paroxetine (Paxil).
  • Antidepressants. Prescribed to treat major depressive disorder, dysthymic disorder, and bipolar disorder. Popular antidepressants include venlafaxine (Effexor), nefazodone (Serzone), bupropion (Wellbutrin), MAOI inhibitors such as phenelzine (Nardil) and tranylcypromine (Parnate); selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft); tricyclic antidepressants such as amitriptyline (Elavil), doxepin hydrochloride (Sinequan), desipramine (Norpramin), and perphenazine/amitriptyline combinations (Etrafon).
  • Antimanic agents. This category includes medications used to treat mania associated with bipolar disorder (or manic-depressive disorder) such as divalproex sodium (Depakote) and lithium carbonate (Lithium, Eskalith, Lithobid, Tegrator).
  • Antipanic agents. Prescribed to treat the panic symptoms that are a defining feature of many anxiety disorders. Medications include clonazepam (Klonopin), paroxetine (Paxil), alprazolam (Xanax), and sertraline (Zoloft).
  • Antipsychotic agents. Also known as neuroleptic agents, these medications are used to manage psychosis related to schizophrenia, delusional disorder, and brief psychotic disorder. They include clozapine (Clozaril), haloperidol (Haldol), loxapine (Loxitane), molindone (Moban), thiothixene (Navane), risperidone (Risperdal), and olanzapine (Zyprexa); also includes phenothiazines such as prochlorperazine (Compazine), trifluoperazine hydrochloride (Stelazine), and chlorpromazine (Thorazine).
  • Obsessive-compulsive disorder medications. Drugs used to treat OCD include fluvoxamine (Luvox), paroxetine (Paxil), fluoxetine (Prozac), and sertraline (Zoloft).
  • Psychostimulants. Also known as central nervous system stimulants, these medications are used to treat attention deficit disorders (ADD and ADHD) and narcolepsy. They include methylphenidate hydrochloride (Methylin, Ritalin) and methaamphetamines (Desoxyn, Dexedrine, and Dextro Stat).

Side effects

There are a number of side-effects associated with psychotherapeutic agents. These can include, and are not limited to, dry mouth, drowsiness, disorientation, delirium, agitation, tremor, irregular heartbeat, headache, insomnia, gastrointestinal distress, nausea, menstrual irregularity, weight gain, weight loss, loss of sex drive, skin rashes, and sweating. Patients should inform their healthcare provider if they experience any of these side effects. In some cases, a dosage adjustment or change of prescription can alleviate any discomfort caused by them. Additional medications may also be prescribed to address severe side effects (e.g., anticholinergic medication may be prescribed for muscle spasms caused by antipsychotic medications).

Tardive dyskinesia, a condition characterized by involuntary movements of the mouth and other locations on the body, has been reported in some patients who take antipsychotic medication on a long-term basis. In some cases, the condition is permanent, although discontinuing or changing medication may halt or reverse it in some patients.

Agranulocytosis, a potentially serious illness in which the white blood cells that typically fight infection in the body are destroyed, is a possible side effect of clozapine, another antipsychotic. Patients taking this medication should undergo weekly blood tests to monitor their white blood cell counts.


Psychotherapeutic agents can be contraindicated (not recommended for use) in patients with certain medical conditions. They may also interact with other prescription and over-the-counter medications, either magnifying or reducing the intended effects of one or both drugs. In some circumstances, they can trigger serious, even life-threatening, physical side effects. For this reason, individuals who are prescribed psychoactive medication should inform their mental healthcare provider and any other prescribing doctor of all medications they are taking, and of any medical conditions they have not yet disclosed.

Monoamine oxidase inhibitors (MAOIs) such as tranylcypromine (Parnate) and phenelzine (Nardil) block the action of monoamine oxidase (MAO), a chemical agent of the central nervous system. Patients who are prescribed MAOIs must eliminate foods high in tyra-mine (found in aged cheeses, red wines, and meats) from their diets to avoid potentially serious hypotensive side effects.

Patients taking Lithium, an antimanic medication, must carefully monitor their salt intake. Diarrhea, sweating, fever, change in diet, or anything else that lowers the level of sodium in their system can result in a toxic build up of Lithium, which can result in slurred speech, confusion, irregular heart beat, vomiting, blurred vision, and possibly death.

Certain psychoactive drugs are lethal in excessive doses, and therefore may not be a viable treatment option for patients at risk for suicide unless they can be dispensed in a controlled manner.

Many psychoactive drugs are contraindicated in pregnancy, particularly in the first trimester. Patients should check with their doctor about the risks associated with psychotherapeutic medications and possible treatment options when planning a pregnancy.

Paula Ford-Martin

Further Reading

Medical Economics Company. The Physicians Desk Reference (PDR). 54th edition. Montvale, NJ: Medical Economics Company, 2000.

Further Information

National Institute of Mental Health (NIMH). 6001 Executive Boulevard, Rm. 8184, MSC 9663, Bethesda, MD, USA. 20892-9663, fax: (301)443-4279, (301)443-4513. Email: nimhinfo@nih.gov. http://www.nimh.nih.gov.

Additional topics

Psychology EncyclopediaPsychological Dictionary: Perception: early Greek theories to Zombie