What is mental illness?
Mental illness is a general term that refers to a group of brain disorders that affect the way a person thinks, feels, behaves, and/or relates to others and to his or her surroundings. Although the symptoms of mental illness can vary from mild to severe, a person with mental illness often is unable to cope with life’s daily routines and demands.
The term "mental illness" is not entirely accurate, since there are many "physical" factors—including heredity and brain chemistry—that might be involved in the development of a mental illness.
Types of mental disorders
There are many different disorders that are recognized as mental illnesses. The more common types include:
Anxiety disorders — People with anxiety disorders respond to certain objects or situations with fear and dread, as well as with physical signs of anxiety (nervousness), such as a rapid heart rate and sweating. An anxiety disorder is diagnosed if the person’s response is not appropriate for the situation, if the person cannot control the response, or if the anxiety interferes with normal functioning. Anxiety disorders include obsessive-compulsive disorder, panic disorder, social anxiety disorder, and specific phobias (an unreasonable fear caused by the presence or thought of a specific object or situation, such as a fear of snakes).
Affective (mood) disorders — These disorders involve persistent feelings of sadness or periods of feeling overly happy. The most common affective disorders are depression, mania, and bipolar disorder.
Psychotic disorders — Psychotic disorders involve distorted awareness and thinking. Two of the most common symptoms of psychotic disorders are hallucinations—the experience of images or sounds that are not real, such as hearing voices—and delusions—false beliefs that a person accepts as true, despite evidence to the contrary. Schizophrenia is an example of a psychotic disorder.
Eating disorders — Eating disorders involve extreme emotions, attitudes, and behaviors involving weight and food. Anorexia nervosa, bulimia nervosa, and binge eating disorder are the most common eating disorders.
Impulse control and addiction disorders — People with impulse control disorders are unable to resist urges, or impulses, to perform acts that could be harmful to themselves or others. Pyromania (starting fires), kleptomania (stealing), and compulsive gambling are examples of impulse control disorders. Alcohol, drugs, and sex are common objects of addictions. Often, people with these disorders become so involved with the objects of their addiction that they begin to ignore responsibilities and relationships.
Personality disorders — People with personality disorders have extreme and inflexible personality traits that are distressing to the person and/or cause problems in work, school, or social relationships. In addition, the person’s patterns of thinking and behavior significantly differ from the expectations of society and are so rigid that they interfere with the person’s normal functioning. Examples include antisocial personality disorder, obsessive-compulsive personality disorder, and paranoid personality disorder.
Other, less common types of mental disorders include:
Adjustment disorder — Adjustment disorder occurs when a person develops emotional or behavioral symptoms in response to a stressful event or situation. The stressors might include natural disasters, such as an earthquake or tornado; events or crises, such as a car accident or the diagnosis of a major illness; or interpersonal problems, such as a divorce, death of a loved one, loss of a job, or a problem with substance abuse. Adjustment disorder usually begins within three months of the event or situation and ends within six months after the stressor stops or is eliminated.
Dissociative disorders — People with these disorders suffer severe disturbances or changes in memory, consciousness, identity, and general awareness of themselves and their surroundings. These disorders usually are associated with overwhelming stress, which might be the result of traumatic events, accidents, or disasters that might be experienced or witnessed by the individual. Dissociative identity disorder, formerly called multiple personality disorder, and depersonalization disorder are examples of dissociative disorders.
Factitious disorders — Factitious disorders are conditions in which physical and/or emotional symptoms are experienced in order to place the individual in the role of a patient or a person in need of help.
Sexual and gender disorders — These include disorders that affect sexual desire, performance and behavior. Sexual dysfunction, gender identity disorder, and the paraphilias are examples of sexual and gender disorders.
Somatoform disorders — A person with a somatoform disorder—formerly known as psychosomatic disorder ("soma" means body)—experiences physical symptoms of an illness even though a doctor can find no medical cause for the symptoms.
Tic disorders — People with tic disorders make sounds or display body movements that are repeated, quick, sudden, and/or uncontrollable. (Sounds that are made involuntarily are called vocal tics.) Tourette syndrome is an example of a tic disorder.
Further, other disorders — including various sleep-related problems and many forms of dementia, including Alzheimer’s disease — are sometimes classified as mental illnesses because they involve the brain.
What are the symptoms of mental illness?
Symptoms will vary depending on the type and severity of the disorder. Some general symptoms that might suggest a mental disorder include:
In adults
- Confused thinking
- Long-lasting sadness or irritability
- Extreme highs and lows in mood
- Excessive fear, worrying, or anxiety
- Social withdrawal
- Dramatic changes in eating or sleeping habits
- Strong feelings of anger
- Delusions or hallucinations
- Increasing inability to cope with daily problems and activities
- Thoughts of suicide
- Denial of obvious problems
- Many unexplained physical problems
- Abuse of drugs and/or alcohol
In older children and pre-teens
- Abuse of drugs and/or alcohol
- Inability to cope with daily problems and activities
- Changes in sleeping and/or eating habits
- Excessive complaints of physical problems
- Defying authority, skipping school, stealing, or damaging property
- Intense fear of gaining weight
- Long-lasting negative mood, often along with poor appetite and thoughts of death
- Frequent outbursts of anger
In younger children
- Changes in school performance
- Poor grades despite strong efforts
- Excessive worrying or anxiety
- Hyperactivity
- Persistent nightmares
- Persistent disobedience or aggressive behavior
- Frequent temper tantrums
What causes mental illness?
Mental illness is not the result of personal weakness, a character defect, or poor upbringing, and recovery from a mental illness is not simply a matter of will and self-discipline. Although the exact cause of most mental disorders is not known, it is becoming clear through research that many of these disorders are caused by a combination of genetic, biological, psychological, and environmental factors.
Heredity (genetics) — Many mental disorders run in families, suggesting that the disorders—or more accurately, a susceptibility (greater likelihood of being affected) to the disorders—might be passed on from parents to children through genes. (Genes are the basic biological unit of heredity. They contain instructions for the function of each cell in the body.) Experts believe many mental disorders are linked to multiple genes—not just one, as with many diseases—which is why a person inherits a susceptibility. The disorder itself occurs from the interaction of multiple genes and other factors—such as psychological trauma and environmental stressors—which can influence, or trigger, the disorder in a person who has an inherited susceptibility.
Biology — Some mental disorders have been linked to special chemicals in the brain called neurotransmitters. Neurotransmitters help nerve cells in the brain communicate with each other. If these chemicals are out of balance or are not working properly, messages might not make it through the brain correctly, leading to symptoms. In addition, defects in or injury to certain areas of the brain have also been linked to some mental disorders.
Psychological trauma — Some mental disorders might be triggered by psychological trauma suffered as a child, such as severe emotional, physical or sexual abuse; a significant early loss, such as the loss of a parent; and neglect.
Environmental stressors — Certain stressors—such as a death or divorce, a dysfunctional family life, changing jobs or schools, and substance abuse—can trigger a disorder in a person who might be at risk for developing a mental illness.
How common is mental illness?
Mental disorders are common, more common than cancer, diabetes, or heart disease. According to the United States Surgeon General, an estimated 23 percent of American adults (those ages 18 and older)—about 44 million people—and about 20 percent of American children suffer from a diagnosable mental disorder during a given year. Further, more than 7 million Americans adults, and more than 5 million children and adolescents suffer from a serious mental disorder (one that significantly interferes with functioning).
Major depression, bipolar disorder, schizophrenia, and obsessive-compulsive disorder are among this country’s top 10 leading causes of disability. Mental disorders cost this nation nearly $150 billion each year in mental health services and lost productivity due to death or disability. Mental disorders account for nearly 25 million annual office visits to doctors. People with mental illness fill almost 21 percent of all hospital beds at any given time.
Mental illness does not discriminate. It can affect people of any age, income or education level, or cultural background. Although mental illness affects both males and females, certain disorders—such as eating disorders—tend to occur more often in females, and other disorders—such as attention deficit hyperactivity disorder (ADHD)—more commonly occur in children.
How is mental illness diagnosed?
If symptoms are present, the doctor will begin an evaluation of the person by performing a complete medical history and physical examination. Although there are no laboratory tests to specifically diagnose mental illness, the doctor might use various diagnostic tests to rule out physical illness as the cause of the symptoms. If no physical illness is found, the person might be referred to a psychiatrist or psychologist, health care professionals who are specially trained to diagnose and treat mental illnesses.
Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a person for a mental illness. The doctor bases his or her diagnosis on the person’s report of symptoms—including any social or functional problems caused by the symptoms—and on his or her observation of the person’s attitudes and behavior. The doctor then determines if the person’s symptoms and degree of disability point to a diagnosis of a specific disorder. The standard manual used for the diagnosis of recognized mental illness is the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), which is compiled by the American Psychiatric Association.
How is mental illness treated?
A mental illness is like many physical problems—such as diabetes or heart disease—that require ongoing treatment. Fortunately, much progress has been made in the last two decades in the treatment of people with mental illnesses. As a result, many mental disorders can be effectively treated with one or a combination of the following therapies:
Medication — Many mental disorders can be effectively treated with medications, such as anti-depressants, anti-anxiety medications, and anti-psychotic drugs.
Psychotherapy — Psychotherapy (a type of counseling) addresses the emotional response to mental illness. It is a process through which trained mental health professionals help people deal with their illness, often by talking through strategies for understanding and dealing with their symptoms, thoughts and behaviors. Therapy might be aimed at the individual, the family, or both.
Group therapy — Some people with mental disorders might benefit from group therapy, where they can find support, and openly discuss their feelings and concerns with others who share common experiences and problems.
Specific therapies — Specific strategies aimed at changing thinking and behavior might be used. These include cognitive-behavior therapy and behavior modification.
Other treatment methods available include:
Alternative therapies — People with anxiety, pain, or other uncomfortable symptoms might find relief through certain alternative therapies, such as water therapy, therapeutic massage, meditation, biofeedback, or another type of relaxation therapy.
Creative therapies — These might include art therapy, music therapy or play therapy.
Hypnotherapy — Hypnotherapy promotes relaxation and can thereby lower anxiety. It also is useful by making people with mental illness more comfortable discussing their problems with a therapist, and by allowing the patient to discuss issues that might be frightening or unknown to his or her conscious mind.
Electroconvulsive therapy (ECT) — During this procedure, electrodes are attached to the patient’s head, and a series of electric shocks are delivered to the brain to induce seizures. The seizures cause the release of chemicals in the brain, including the neurotransmitters that help deliver messages from one brain cell to another. This therapy has been shown to be successful for treating severe depression.
What is the outlook for people with mental illness?
When diagnosed early and treated properly, many people fully recover from their mental illness or are able to successfully control their symptoms. Although some people become disabled because of a chronic or severe mental illness, many people who experience a mental illness are able to live full and productive lives. In fact, as many as eight in 10 people suffering from mental disorders can effectively return to their normal activities if they receive appropriate treatment.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 2/11/2005
