Mental Illness in Children

Medically Reviewed by Smitha Bhandari, MD on September 15, 2023
6 min read

According to the U.S. Surgeon General, about 20% of American children suffer from a diagnosable mental illness during a given year. Further, nearly 5 million American children and adolescents suffer from a serious mental illness (one that significantly interferes with their day-to-day life).

Children can suffer from the following mental illnesses:

  • Anxiety disorders: Children with anxiety disorders respond to certain things or situations with fear and dread, as well as with physical signs of anxiety (nervousness), such as a rapid heartbeat and sweating.
  • Disruptive behavior disorders: Children with these disorders tend to defy rules and often are disruptive in structured environments, such as school.
  • Eating disorders:Eating disorders involve intense emotions and attitudes, as well as unusual behaviors, associated with weight and/or food.
  • Elimination disorders: These disorders affect behavior related to the elimination of body wastes (feces and urine).
  • Affective (mood) disorders: These disorders, including depression, involve persistent feelings of sadness and/or rapidly changing moods.
  • Schizophrenia: This is a serious disorder that involves distorted perceptions and thoughts.
  • Tic disorders: These disorders cause a person to perform repeated, sudden, involuntary and often meaningless movements and sounds, called tics.
  • ADHD (attention deficit hyperactivity disorder): Children with this disorder are hyperactive and have trouble controlling their impulses and paying attention. ADHD is the most commonly diagnosed mental disorder in children.

Some of these illnesses, such as anxiety disorders, eating disorders, mood disorders, and schizophrenia, can occur in adults as well as children. Others, such as behavior and development disorders, elimination disorders, and learning and communication disorders, begin in childhood only, although they can continue into adulthood. In rare cases, tic disorders can develop in adults. It is not unusual for a child to have more than one disorder.

Children's symptoms vary depending on the type of mental illness, but some of the general symptoms include:

  • Changes in school performance, such as poor grades despite good efforts
  • 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 ailments
  • Defying authority, skipping school, stealing, or damaging property
  • Intense fear of gaining weight
  • Long-lasting negative moods, often accompanied by poor appetite and thoughts of death
  • Frequent outbursts of anger
  • Loss of interest in friends and activities they usually enjoy
  • Significant increase in time spent alone
  • Excessive worrying or anxiety
  • Hyperactivity
  • Persistent nightmares or night terrors
  • Persistent disobedience or aggressive behavior
  • Frequent temper tantrums
  • Hearing voices or seeing things that are not there (hallucinations)

The exact cause of most mental illnesses is not known, but research suggests that a combination of factors, including heredity, biology, psychological trauma, and environmental stress, may be involved.

  • Heredity (genetics): Mental illness tends to run in families, which means the likelihood to develop a mental disorder may be passed on from parents to their children.
  • 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 not working properly, messages may not make it through the brain correctly, leading to symptoms. In addition, defects in or injury to certain areas of the brain also have been linked to some mental illnesses.
  • Psychological trauma: Some mental illnesses may be triggered by psychological trauma, such as
    • severe emotional, physical, or sexual abuse
    • an important early loss, such as the loss of a parent
    • neglect -- both emotional and physical
  • Environmental stress: Stressful or traumatic events can trigger a mental illness in a person with a vulnerability to a mental disorder.

As with adults, mental illnesses in children are diagnosed based on signs and symptoms that suggest a particular disorder. However, this process can be especially challenging with children. Many behaviors that are seen as symptoms of mental disorders, such as shyness, anxiety (nervousness), strange eating habits, and temper tantrums, can occur as a normal part of a child's development. Behaviors become symptoms when they occur very often, last a long time, occur at an unusual age or cause significant disruption to the child's and/or family's ability to function.

If symptoms are present, the doctor will begin an evaluation by performing a complete medical history and physical exam. Although there are no lab tests to specifically diagnose mental disorders, the doctor may use various tests, such as X-rays and blood tests, to rule out physical illness or medication side effects as the cause of the symptoms.

If no physical illness is found, the child may be referred to a child and adolescent psychiatrist or psychologist, mental health professionals who are specially trained to diagnose and treat mental illness in children and teens. Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a child for a mental disorder. The doctor bases their diagnosis on reports of the child's symptoms and their observation of the child's attitude and behavior. The doctor often must rely on reports from the child's parents, teachers, and other adults because children often have trouble explaining their problems or understanding their symptoms.

Mental illnesses are like many medical disorders that require ongoing treatment. Although much progress has been made in the treatment of adults with mental disorders, the treatment of children is not as well understood. Experts are still exploring which treatments work best for which conditions in children. For now, many of the treatment options used for children, including many medications, are the same as what is used to treat adults. The most common treatment options used include:

  • Medication: Many mental illnesses can be effectively treated with medications in combination with therapy. The drugs often used to treat mental disorders in children include antidepressants, anti-anxiety drugs, stimulants, mood stabilizing drugs, and antipsychotics.
  • Psychotherapy: Psychotherapy (a type of counseling) addresses the emotional response to mental illness. It is a process in 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. Types of psychotherapy often used with children are supportive, cognitive behavioral, interpersonal, group, and family therapy.
  • Creative therapies: Certain therapies, such as art therapy or play therapy, may be helpful, especially for young children who may have trouble communicating their thoughts and feelings. 

When treated appropriately and early, many children can fully recover from their mental illness or successfully control their symptoms. While some children become disabled adults because of a chronic or severe disorder, many people who have a mental illness are able to live full and productive lives.

It is very important to seek treatment for your child if they are displaying any symptoms of mental illness. Without treatment, many mental disorders can continue into adulthood and lead to problems in all areas of the person's adult life. People with untreated mental disorders are at high risk for many problems, including alcohol or drug abuse, and violent or self-destructive behavior, even suicide.

To date, most research on mental illness has centered on mental disorders in adults. However, the mental health community has now begun to focus on mental illness in children. Researchers are looking at childhood development in terms of what is normal and abnormal, trying to understand how factors affecting development can have an impact on mental health. The goal is to try to predict, and ultimately, prevent, developmental problems that could lead to mental illness. A key part of this research is the identification of risk factors -- factors that increase a child's chances of developing a mental disorder. In addition, the mental health community is calling for additional research on medications used to treat children with mental disorders.

Most mental illnesses are caused by a combination of factors and cannot be completely prevented. However, if symptoms are recognized and treatment is started early, many of the distressing and disabling effects of a mental illness may be prevented or at least minimized.