A number of psychoactive drugs are highly effective and widely used by psychiatrists and other medical doctors. These drugs are often categorized according to the disorder they are primarily prescribed for. For example, antidepressants are used to treat depression.

The most widely used class of antidepressants is selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine, sertraline, paroxetine, andcitalopram (see Mood Disorders:Drug therapy). Other classes of antidepressants include serotonin-norepinephrine reuptake inhibitors (SNRIs), such as venlafaxine, duloxetine, or desvenlafaxine, and norepinephrine–dopamine reuptake inhibitors, such as bupropion. Tricyclic antidepressants such as amitriptlyine and nortriptyline are seldom used, unless people also have a disorder causing pain that interferes with activities and work. Monoamine oxidase inhibitors may be effective but are rarely used except when other antidepressants have not worked.

Older antipsychotic drugs, such as chlorpromazine, haloperidol, and thiothixene, are helpful in treating psychotic disorders such as schizophrenia (seeAntipsychotic drugs). Newer antipsychotic drugs (commonly called atypical or 2nd-generation antipsychotics), such as risperidone, olanzapine,quetiapine, ziprasidone, and aripiprazole, are now commonly used as initial treatment. For people who do not respond to other antipsychotic drugs,clozapine is being increasingly used.

SSRIs and antianxiety drugs, such as clonazepam, lorazepam, and diazepam, as well as antidepressants, are used to treat anxiety disorders, such as panic disorder and phobias. Mood stabilizers, such as lithium, carbamazepine, valproate, lamotrigine, and topiramate, are used to treat bipolar disorder.

With electroconvulsive therapy, electrodes are attached to the head, and while the person is sedated, a series of electrical shocks are delivered to the brain to induce a brief seizure. This therapy has consistently been shown to be the most effective treatment for severe depression. Many people treated with electroconvulsive therapy experience temporary memory loss. However, contrary to its portrayal in the media, electroconvulsive therapy is safe and rarely causes any other complications. The modern use of anesthetics and muscle relaxants has greatly reduced any risk.

In recent years, significant advances have been made in the field of psychotherapy. Psychotherapy, sometimes referred to as talk therapy, works on the assumption that the cure for a person’s suffering lies within that person and that this cure can be facilitated through a trusting, supportive relationship with a psychotherapist. By creating an empathetic and accepting atmosphere, the therapist often is able to help the person identify the source of the problems and consider alternatives for dealing with them. The emotional awareness and insight that the person gains through psychotherapy often results in a change in attitude and behavior that allows the person to live a fuller and more satisfying life.

Psychotherapy is appropriate in a wide range of conditions. Even people who do not have a mental health disorder may find psychotherapy helpful in coping with such problems as employment difficulties, bereavement, or chronic illness in the family. Group psychotherapy, couples therapy, and family therapy are also widely used.

Most mental health practitioners practice one of six types of psychotherapy: supportive psychotherapy, psychoanalysis, psychodynamic psychotherapy, cognitive therapy, behavioral therapy, or interpersonal therapy.

Supportive psychotherapy, which is most commonly used, relies on the empathetic and supportive relationship between the person and the therapist. It encourages expression of feelings, and the therapist provides help with problem solving. Problem-focused psychotherapy, a form of supportive therapy, may be used successfully by primary care doctors.

Psychoanalysis is the oldest form of psychotherapy and was developed by Sigmund Freud in the first part of the 20th century. The person typically lies on a couch in the therapist’s office 4 or 5 times a week and attempts to say whatever comes to mind—a practice called free association. Much of the focus is on understanding how past patterns of relationships repeat themselves in the present. The relationship between the person and the therapist is a key part of this focus. An understanding of how the past affects the present helps the person develop new and more adaptive ways of functioning in relationships and in work settings.

Psychodynamic psychotherapy, like psychoanalysis, emphasizes the identification of unconscious patterns in current thoughts, feelings, and behaviors. However, the person is usually sitting instead of lying on a couch and attends only 1 to 3 sessions per week. In addition, less emphasis is placed on the relationship between the person and therapist.

Cognitive therapy helps people identify distortions in thinking and understand how these distortions lead to problems in their lives. The premise is that how people feel and behave is determined by how they interpret experiences. Through the identification of core beliefs and assumptions, people learn to think in different ways about their experiences, reducing symptoms and resulting in improvement in behavior and feelings.

Behavioral therapy is related to cognitive therapy. Sometimes a combination of the two, known as cognitive-behavioral therapy, is used. The theoretical basis of behavioral therapy is learning theory, which says that abnormal behaviors are due to faulty learning. Behavioral therapy involves a number of interventions that are designed to help the person unlearn maladaptive behaviors while learning adaptive behaviors. Exposure therapy, often used to treat phobias, is one example of a behavioral therapy (see ).

Interpersonal therapy was initially conceived as a brief psychologic treatment for depression and is designed to improve the quality of a depressed person’s relationships. It focuses on unresolved grief, conflicts that arise when people have to fill roles that differ from their expectations (such as when a woman enters a relationship expecting to be a stay-at-home mother and finds that she must also be the major provider for the family), transitions in social roles (such as going from being an active worker to being retired), and difficulty communicating with others. The therapist teaches the person to improve aspects of interpersonal relationships, such as overcoming social isolation and responding in a less habitual way to others.

Although people sometimes assume that changes in personality, thinking, or behavior are all due to a mental disorder, there are many possible causes. All causes ultimately involve the brain, but dividing them into four categories can be helpful:

Of these causes, drugs are the most common cause overall, followed by mental disorders.

Drugs may affect personality or behavior when they cause

Rarely, certain antibiotics and drugs used to treat high blood pressure cause changes in personality and behavior.

Mental disorders include

Disorders affecting mainly the brain include

Bodywide disorders that also affect the brain include

Less commonly, Lyme disease, sarcoidosis, syphilis, or a vitamin deficiency causes personality and behavior changes.

During the initial evaluation, doctors try to determine whether symptoms are due to a mental or physical disorder.

The following information can help people decide when a doctor’s evaluation is needed and help them know what to expect during the evaluation.

The underlying condition is corrected or treated when possible. Whatever the cause, people who are a danger to themselves or others typically need to be hospitalized and treated whether they are willing or not. Many states require that such decisions be made by someone appointed to make health care decisions for the mentally ill person (see Default Surrogate Decision Making). If the person has not appointed a decision maker, doctors may contact the next of kin, or a court may appoint an emergency guardian. People who are not dangerous to themselves or others can refuse evaluation and treatment, despite the difficulties their refusal may create for themselves and their family.