Drugs to Treat Mental Illness

Medically Reviewed by Jennifer Casarella, MD on October 26, 2022
6 min read

There are several different types of drugs available to treat mental illnesses. Some of the most commonly used are antidepressants, anti-anxiety, antipsychotic, mood stabilizing, and stimulant medications.

When treating depression, several drug options are available. Some of the most commonly used include:

Your health care provider can determine which medication is right for you. Remember that medications usually take 4 to 6 weeks to become fully effective. And if one drug does not work, there are many others to try.

In some cases, a combination of antidepressants sometimes called augmentation, may be necessary. Sometimes an antidepressant combined with a different type of drug, such as a mood stabilizer (like Lithium), a second antidepressant, or atypical antipsychotic drug, is the most effective treatment.

Side effects vary, depending on what type of drug you are taking, and may improve once your body adjusts to the medication.

If you decide to stop taking your antidepressants, it is important that you gradually reduce the dose over a period of several weeks. With many antidepressants, quitting them abruptly can cause discontinuation symptoms or speed the risk for depression relapse. It is important to discuss quitting (or changing) medications with your healthcare provider first.

Antidepressants, particularly the SSRIs, may also be effective in treating many types of anxiety disorders.

Other anti-anxiety medications include the benzodiazepines, such as alprazolam (Xanax), clonazepam (Klonopin), diazepam (Valium), and lorazepam (Ativan). These drugs carry a risk of addiction, so they are not as desirable for long-term use. Other possible side effects include drowsiness, poor concentration, and irritability.

The drug buspirone (Buspar) is a unique serotonergic drug that is non-habit-forming and often used to treat generalized anxiety disorder (GAD).

Some antiseizure medicines, such as gabapentin (Neurontin) or pregabalin (Lyrica) are sometimes used "off label" (without an official FDA indication) to treat certain forms of anxiety.

Finally, some conventional as well as atypical antipsychotic drugs have been shown to reduce anxiety symptoms in the context of treating depression or psychosis, and may also sometimes be used "off label" as treatments for anxiety.

Antipsychotics are a class of drugs used commonly to treat psychotic disorders -- conditions in which thinking can be irrational, and people have false beliefs (delusions) or perceptions (hallucinations) -- and sometimes to treat mood disorders such as bipolar disorder or major depression. Different antipsychotics vary in their side effects, and some people have more trouble with certain side effects than with others. The doctor can change medications or dosages to help minimize unpleasant side effects. A drawback to some antipsychotic medications is their potential to cause side effects such as sedation and problems with involuntary movements, weight gain, and changes in blood sugar or cholesterol, which require periodic laboratory monitoring. Different antipsychotics have different side effect profiles, so you'll work with your doctor to choose the right drug for you.

Many side effects of antipsychotic drugs are mild and many go away after the first few weeks of treatment. Common side effects may include:

  • Drowsiness
  • Rapid or irregular heartbeat
  • Dizziness when changing positions
  • Decrease in sexual interest or ability
  • Problems with menstrual periods
  • Skin rashes or skin sensitivity to the sun
  • Weight gain
  • Muscle spasms
  • Restlessness and pacing
  • Slowing down of movement and speech
  • Shuffling walk
  • Menstrual irregularities in women

There are, however, a few serious side effects that are possible, especially with long-term use of antipsychotic medications. These side effects include:

  • Tardive dyskinesia: This is a movement disorder that results in unusual and uncontrollable movements, usually of the tongue and face (such as sticking out the tongue and smacking the lips), and sometimes jerking and twisting movements of other parts of the body. It can be treated by taking deutetrabenazine (Austedo) or valbenazine (Ingrezza).
  • Neuroleptic malignant syndrome: This is a potentially fatal disorder characterized by severe muscle rigidity (stiffening), fever, sweating, high blood pressure, delirium, and sometimes coma.
  • Agranulocytosis: This is a condition marked by a sharp decrease in the number of infection-fighting white blood cells. This condition can leave the person prone to infection and at greater risk of death. Agranulocytosis has been particularly linked with Clozaril, where it may occur in 1 in 100 patients. People taking Clozaril must have regular blood tests to closely monitor their white blood cell count. However, all antipsychotics carry a warning label from the FDA noting that as a class they have a risk for lowering someone's white blood cell count.
  • Changes in Blood Sugar and Cholesterol: Some atypical antipsychotics can cause increases in blood sugar (which could eventually lead to diabetes) and blood lipids such as cholesterol and triglycerides. Periodic blood tests are necessary to monitor these factors.

If antipsychotic drug side effects are particularly troublesome, your doctor may change medications or dosages or sometimes add additional medicines to counteract side effects like weight gain or high blood lipids. The newer atypical antipsychotic medications appear to be much better tolerated, with fewer side effects such as movement disorders or drowsiness. They do, though, require monitoring for weight and metabolic risks, which appear to be higher than with older-generation antipsychotics.

Newer antipsychotic drugs include:

Olanzapine/samidorphan(Lybalvi)

Another group of drugs called stimulants may be used for certain disorders, primarily attention deficit hyperactivity disorder (ADHD). The most commonly used stimulants include amphetamine salt combo (Adderall, Adderall XR), methylphenidate (Daytrana) patch, dextroamphetamine (Dexedrine), lisdexamfetamine (Vyvanse), and methylphenidate (Concerta, Quillivant XR, Ritalin) in pill form. Recently, the FDA approved a once a day treatment of mixed salts of a single-entity amphetamine product called dextroamphetamine-amphetamine (Mydayis).

A class of drugs, called alpha agonists, are nonstimulant medicines that are also sometimes used to treat ADHD.  Examples include clonidine (Catapres) and guanfacine (Intuniv). 

Atomoxetine (Strattera) also has FDA-approval for the treatment of ADHD. It is a non-stimulant more similar to the SNRI antidepressants. But the agency has also issued warnings that children and teens who take it may have suicidal thoughts.

The antidepressant drug, buproprion (Wellbutrin) is also used to treat ADHD at times.

The FDA requires all ADHD drugs to include patient medication guides that detail serious outcomes from the use of the drugs, including a slightly higher risk of stroke, heart attack and sudden death, and psychiatric problems like becoming manic or psychotic.

Many drugs used to treat mental disorders in adults are also used to treat the same illnesses in children. However, doctors often adjust the doses given and monitor more closely.

The FDA has determined that antidepressant drugs can increase the risk of suicidal thinking and behavior in children and adolescents with depression and other psychiatric disorders. If you have questions or concerns, discuss them with your healthcare provider.

Drugs cannot cure mental illnesses. Rather, they work to control many of the most troubling symptoms, often enabling people with mental disorders to return to normal or near-normal functioning. Reducing symptoms with medication can also enhance the effectiveness of other treatments, such as psychotherapy (a type of counseling).