Mayo Clinic Health Library

Mental illness

Updated: 09-15-2012


Mental illness refers to a wide range of mental health conditions — disorders that affect your mood, thinking and behavior. Examples of mental illness include depression, anxiety disorders, schizophrenia, eating disorders and addictive behaviors.

Many people have mental health concerns from time to time. But a mental health concern becomes a mental illness when ongoing signs and symptoms cause frequent stress and affect your ability to function. A mental illness can make you miserable and can cause problems in your daily life, such as at work or in relationships. In most cases, mental illness symptoms can be managed with a combination of medications and counseling (psychotherapy).



Signs and symptoms of mental illness can vary, depending on the particular disorder, circumstances and other factors. Mental illness symptoms can affect emotions, thoughts and behaviors.

Examples of signs and symptoms include:

  • Feeling sad or down
  • Confused thinking or reduced ability to concentrate
  • Excessive fears or worries
  • Extreme mood changes of highs and lows
  • Withdrawal from friends and activities
  • Significant tiredness, low energy or problems sleeping
  • Detachment from reality (delusions), paranoia or hallucinations
  • Inability to cope with daily problems or stress
  • Extreme feelings of guilt
  • Alcohol or drug abuse
  • Major changes in eating habits
  • Sex drive changes
  • Excessive anger, hostility or violence
  • Suicidal thinking

Sometimes symptoms of a mental health disorder appear as physical problems, such as abdominal pain, back pain, headache, or other unexplained aches and pains.

Is it mental illness?
In general, signs and symptoms may indicate a mental illness when they make you miserable and interfere with your ability to function in your daily life. You may have trouble coping with stress, anger or other emotions. Or you may find it difficult to handle family, work or school responsibilities, or have serious legal or financial problems.

With some types of mental illness, though, such as schizophrenia or bipolar disorder, you may not realize the extent of your problems — instead, it may be family members or friends who first become aware that you have a mental illness.

When to see a doctor
If you have any signs or symptoms of a mental illness, see your doctor, mental health provider or other health professional. Most mental illnesses don't improve on their own, and if untreated, a mental illness may get worse over time and cause serious problems.

If you have suicidal thoughts
Suicidal thoughts and behavior are common with some mental illnesses. If you think you may hurt yourself or attempt suicide, get help right away:

  • Call 911 or your local emergency number immediately.
  • Call a suicide hotline number — in the United States, call the National Suicide Prevention Lifeline at 800-273-TALK (800-273-8255) to reach a trained counselor. Use that same number and press 1 to reach the Veterans Crisis Line.
  • Reach out to a close friend or loved one — even though you may be reluctant to talk about your feelings.
  • Contact a minister, spiritual leader or someone in your faith community.
  • Contact your doctor, other health care provider or mental health specialist.

Suicidal thinking doesn't get better on its own — so get help.

Helping a loved one
If your loved one shows signs of mental illness, have an open and honest discussion with him or her about your concerns. You may not be able to force someone to seek professional care, but you can offer encouragement and support. You can also help your loved one find a qualified doctor or mental health provider and make an appointment. You may even be able to go along to the appointment.

If your loved one has harmed himself or herself, or is seriously considering doing so, take the person to the hospital, or call for emergency help.



Mental illnesses, in general, are thought to be caused by a variety of genetic and environmental factors:

  • Inherited traits. Mental illness is more common in people whose biological (blood) relatives also have a mental illness. Certain genes may increase your risk of developing a mental illness, and your life situation may trigger the actual mental illness.
  • Environmental exposures before birth. Exposure to viruses, toxins, alcohol or drugs while in the womb can sometimes be linked to mental illness.
  • Negative life experiences. Situations in your life, such as the loss of a loved one, financial problems and high stress, can play a role in triggering mental illness. So can an upbringing that leads to poor self-esteem or a history of sexual or physical abuse. Life experiences can lead to unhealthy patterns of thinking linked to mental illness, such as pessimism or distorted ways of thinking.
  • Brain chemistry. Biochemical changes in the brain are thought to affect mood and other aspects of mental health. Naturally occurring brain chemicals called neurotransmitters play a role in some mental illnesses. In some cases, hormonal imbalances affect mental health. It's thought that inherited traits, life experiences and biological factors can all affect brain chemistry linked to mental illnesses.

Risk factors

Certain factors may increase your risk of developing mental health problems, including:

  • Having a biological (blood) relative, such as a parent or sibling, with a mental illness
  • Experiences in the womb — for example, having a mother who was exposed to viruses, toxins, drugs or alcohol during pregnancy
  • Experiencing stressful life situations, such as financial problems, a loved one's death or a divorce
  • Having a chronic medical condition, such as cancer
  • Experiencing brain damage as a result of a serious injury (traumatic brain injury), such as a violent blow to the head
  • Having traumatic experiences, such as military combat or being assaulted
  • Use of illegal drugs
  • Being abused or neglected as a child
  • Having few friends or few healthy relationships
  • Having a previous mental illness

Mental illness is common. About 1 in 4 adults has a mental illness in any given year. About half of U.S. adults will develop a mental illness sometime in their lives. Mental illness can begin at any age, from childhood through later adult years.



Mental illness is a leading cause of disability. Aside from reducing your quality of life, untreated mental illness can cause severe emotional, behavioral and physical health problems. Mental illness can also cause legal and financial problems. Complications linked to mental illness include:

  • Unhappiness and decreased enjoyment of life
  • Family conflicts
  • Relationship difficulties
  • Social isolation
  • Problems with tobacco, alcohol and other drugs
  • Missed work or school, or other problems related to work or school
  • Poverty and homelessness
  • Self-harm and harm to others, including suicide or homicide
  • Increased risk of motor vehicle accidents
  • Weakened immune system, so your body has a hard time resisting colds and other infections
  • Heart disease and other medical conditions

Preparing for your appointment

Whether you schedule an appointment with your primary care doctor to talk about mental health concerns or you're referred to a mental health provider, such as a psychiatrist or psychologist, take steps to prepare for your appointment.

What you can do

  • Write down any symptoms you or people close to you have noticed, and for how long.
  • Write down key personal information, including traumatic events in your past and any current, major stressors.
  • Make a list of your medical information, including other physical or mental health conditions and the names and amounts of medications, herbal remedies or supplements you take.
  • Take a family member or friend along, if possible. Someone who has known you for a long time may be able to share important information with the doctor or mental health professional, with your permission.

Write down a list of questions to ask. These may include:

  • What type of mental illness might I have?
  • Why can't I get over mental illness on my own?
  • How do you treat my type of mental illness?
  • Will counseling or psychotherapy help?
  • Are there medications that might help?
  • How long will treatment take?
  • What can I do to help myself?
  • Do you have any brochures or other printed material that I can have?
  • What websites do you recommend?

In addition to the questions that you've prepared, don't hesitate to ask questions anytime you don't understand something.

What to expect from your doctor
During your appointment, your doctor or mental health provider is likely to ask you a number of questions about your mood, thoughts and behavior. You may be asked such questions as:

  • When did you first notice symptoms?
  • How is your daily life affected by your symptoms?
  • What treatment, if any, have you had for mental illness?
  • What have you tried on your own to feel better or control your symptoms?
  • What things make you feel worse?
  • Have family members or friends commented on your mood or behavior?
  • Do you have biological (blood) relatives with a mental illness?
  • What do you hope to gain from treatment?
  • What medications or over-the-counter herbs and supplements do you take?
  • Do you drink alcohol or use illegal drugs?

Tests and diagnosis

To determine a diagnosis and check for any related complications, you may have these exams and tests:

  • Physical exam. Your doctor will try to rule out physical problems that could cause your symptoms.
  • Lab tests. These may include a check of your thyroid function or a screening for alcohol and drugs, for example.
  • Psychological evaluation. A doctor or mental health provider will talk to you about your symptoms, thoughts, feelings and behavior patterns. You may be asked to fill out a questionnaire to help answer these questions.

Determining which mental illness you have
Sometimes it's difficult to find out which particular mental illness may be causing your symptoms. But taking the time and effort to get an accurate diagnosis will help determine the appropriate treatment.

The defining symptoms for each mental illness are detailed in the Diagnostic and Statistical Manual of Mental Disorders (DSM) published by the American Psychiatric Association. Mental health providers use this manual to diagnose mental conditions, and insurance companies use it to reimburse for treatment. To be diagnosed with a particular mental illness, you must meet the criteria listed in the DSM.

Classes of mental illness
The main classes of mental illness are:

  • Mood disorders. These include disorders that affect how you feel emotionally, such as the level of sadness and happiness. Examples include depression and bipolar disorder.
  • Anxiety disorders. Anxiety is an emotion characterized by the anticipation of future danger or misfortune, accompanied by feeling ill at ease. Examples include generalized anxiety disorder, panic disorder, obsessive-compulsive disorder, phobias and post-traumatic stress disorder.
  • Substance-related disorders. These include problems associated with the misuse of alcohol and illegal or legal drugs.
  • Psychotic disorders. Psychotic disorders cause detachment from reality (delusions, paranoia and hallucinations). The most notable example is schizophrenia, although other classes of disorders can be associated with detachment from reality at times.
  • Cognitive disorders. Cognitive disorders affect your ability to think and reason. They include delirium, dementia and memory problems. Alzheimer's disease is an example of a cognitive disorder.
  • Developmental disorders. This category covers a wide range of problems that usually begin in infancy, childhood or the teenage years. They include autism, attention-deficit/hyperactivity disorder (ADHD) and learning disabilities.
  • Personality disorders. A personality disorder involves a lasting pattern of emotional instability and unhealthy behavior that causes problems in your life and relationships. Examples include borderline personality disorder and antisocial personality disorder.
  • Other disorders. These include disorders of impulse control, sleep, sexual functioning and eating. Also included are dissociative disorders, in which your sense of self is disrupted; somatoform disorders, in which there are physical symptoms with no clear cause; adjustment disorder, in which you have trouble coping during a stressful life event; and mental disorders that are due to general medical conditions.

Treatments and drugs

Your particular treatment depends on the type of mental illness you have, its severity and what works best for you. In many cases, a combination of treatments works best.

If you have a mild mental illness with well-controlled symptoms, treatment from one health care provider may be sufficient. However, often a team approach is appropriate to make sure all your psychiatric, medical and social needs are met. This is especially important for severe mental illnesses, such as schizophrenia.

Your treatment team
Your treatment team may include your:

  • Family or primary care doctor
  • Psychiatrist, a medical doctor who diagnoses and treats mental illnesses
  • Psychotherapist, such as a psychologist or a licensed counselor
  • Pharmacist
  • Social worker
  • Family members

Although psychiatric medications don't cure mental illness, they can often significantly improve symptoms. Psychiatric medications can also help make other treatments, such as psychotherapy, more effective. The best medications for you will depend on your particular situation and how your body responds to the medication.

Here's an overview of some of the most commonly used classes of prescription psychiatric medications:

  • Antidepressant medications. Antidepressants are used to treat various types of depression and sometimes other conditions. Antidepressants can help improve such symptoms as sadness, hopelessness, lack of energy, difficulty concentrating and lack of interest in activities. Different types of antidepressants are grouped by how they affect brain chemistry. The best one for you depends on your particular situation and how your body responds to medication.
  • Mood-stabilizing medications. Mood stabilizers are most commonly used to treat bipolar disorder, which is characterized by alternating episodes of mania and depression. Sometimes mood-stabilizing medications are added to antidepressants to treat depression.
  • Anti-anxiety medications. Anti-anxiety medications are used to treat anxiety disorders, such as generalized anxiety disorder and panic disorder. They may also help reduce agitation and insomnia. These medications are typically fast acting, helping relieve symptoms in as little as 30 to 60 minutes. A major drawback, however, is that they have the potential to cause dependency.
  • Antipsychotic medications. Antipsychotic medications, also called neuroleptics, are typically used to treat psychotic disorders such as schizophrenia. Antipsychotic medications may also be used to treat bipolar disorders or added to antidepressants to treat depression.

Psychotherapy, also called talk therapy or psychological counseling, is a process of treating mental illness by talking about your condition and related issues with a mental health provider. During psychotherapy, you learn about your condition and your moods, feelings, thoughts and behavior. Using the insights and knowledge you gain, you can learn coping and stress management skills.

There are many specific types of psychotherapy, each with its own approach to improving your mental well-being. Psychotherapy often can be successfully completed in a few months, but in some cases, long-term treatment may be helpful. It can take place one-on-one, in a group or along with family members.

Brain-stimulation treatments
Brain-stimulation treatments are sometimes used for depression and some other mental health disorders. They are generally reserved for situations in which medications and psychotherapy haven't worked. They include electroconvulsive therapy (ECT), transcranial magnetic stimulation, vagus nerve stimulation and an experimental treatment called deep brain stimulation.

Make sure you understand all the risks and benefits of any recommended treatment.

Hospitalization and residential treatment programs
Sometimes mental illness becomes so severe that you need psychiatric hospitalization. Hospitalization is generally recommended when you can't care for yourself properly or when you're in immediate danger of harming yourself or someone else. Options include 24-hour inpatient care, partial or day hospitalization, or residential treatment, which offers a supportive place to live. One other option may be intensive outpatient treatment.

Substance abuse treatment
Substance abuse commonly occurs along with mental illness. Often it interferes with treatment and worsens mental illness. If you can't stop using drugs or alcohol on your own, you need treatment. Substance abuse treatments include:

  • Psychotherapy, to learn more about your condition and gain insight
  • Medications, which may help ease withdrawal symptoms or reduce cravings
  • Inpatient treatment, such as withdrawal (detox) treatment
  • Outpatient treatment programs, which require regular attendance for a set period of time
  • Support groups or 12-step programs, such as Alcoholics Anonymous (AA)

Participating in your own care
Working together, you and your health provider can decide which treatment options may be best for you, depending on your symptoms and their severity, your personal preferences, side effects, and other factors. In some cases, a mental illness may be so severe that a doctor, loved one or guardian may need to guide your care until you're well enough to participate in decision making.


Lifestyle and home remedies

In most cases, a mental illness won't get better if you try to treat it on your own without professional care. But you can do some things for yourself that will build on your treatment plan:

  • Stick to your treatment plan. Don't skip therapy sessions. Even if you're feeling better, don't skip your medications. If you stop, symptoms may come back. You could also have withdrawal-like symptoms if you stop a medication too suddenly. If you have bothersome medication side effects or other problems with your treatment, talk to your doctor before making changes.
  • Avoid alcohol and drug use. Using alcohol or illegal drugs can make it difficult to treat a mental illness. If you're addicted, quitting can be a real challenge. If you can't quit on your own, see your doctor or find a support group to help you.
  • Stay active. Exercise can help you manage symptoms such as depression, stress and anxiety. Physical activity can also counteract the effects of some psychiatric medications that may cause weight gain. Consider walking, jogging, swimming, gardening or taking up another form of physical activity that you enjoy. Even light physical activity can make a difference.
  • Don't make important decisions when your symptoms are severe. Avoid decision making when you're in the depth of mental illness symptoms, since you may not be thinking clearly.
  • Prioritize your life. You can reduce the impact of your mental illness by carefully managing your time and energy. Cut back on obligations when necessary, and set reasonable goals for yourself. Give yourself permission to do less when your symptoms are bad. You may find it helpful to make a list of daily tasks, use sticky notes as reminders, or use a planner to structure your time and stay organized.
  • Learn to adopt a positive attitude. Focusing on the positive things in your life can make your life better and may even improve your health. Try to accept changes when they occur, and keep problems in perspective.

Coping and support

Coping with a mental illness can be challenging. Talk to your doctor or therapist about improving your coping skills, and consider these tips:

  • Learn about your mental illness. Include your family, too — this can help the people who care about you understand what you're going through and learn how they can help. Your doctor or therapist may provide information directly or may recommend classes, books or websites.
  • Join a support group. Connecting with others facing similar challenges can help you cope. Support groups for mental illness are available in many communities and online. One good place to start is the National Alliance on Mental Illness.
  • Stay connected with friends and family. Try to participate in social activities, and get together with family or friends regularly. Ask for help when you need it, and be upfront with your loved ones about how you're doing.
  • Keep a journal. Keeping track of your personal life can help you and your mental health provider identify what triggers or improves your symptoms. It's also a healthy way to explore and express pain, anger, fear and other emotions.


There's no sure way to prevent mental illness. However, if you do have a mental illness, taking steps to control stress, to increase your resilience and to boost low self-esteem may help keep your symptoms under control. Follow these steps:

  • Pay attention to warning signs. Work with your doctor or therapist to learn what might trigger your symptoms. Make a plan so that you know what to do if symptoms return. Contact your doctor or therapist if you notice any changes in symptoms or how you feel. Consider involving family members or friends in watching for warning signs.
  • Get routine medical care. Don't neglect checkups or skip visits to your family doctor, especially if you aren't feeling well. You may have a new health problem that needs to be treated, or you may be experiencing side effects of medication.
  • Get help when you need it. Mental health conditions can be harder to treat if you wait until symptoms get bad. Long-term maintenance treatment also may help prevent a relapse of symptoms.
  • Take good care of yourself. Sufficient sleep, healthy eating and regular physical activity are important. Try to maintain a regular schedule. Talk to your doctor if you have trouble sleeping or if you have questions about diet and exercise.