Causes and Warning Signs of Mental Illness

Like adults, children and adolescents can have mental health or substance use problems that interfere with the way they think, feel, and act. Such problems-if not addressed-may interfere with learning and the ability to form and sustain friendships, contribute to disciplinary problems and family conflicts, and increase risky behaviors.

Mental Health Problem Common In Young People

Serious mental health problems often are a factor in drug abuse and suicide. Mental health and substance use problems are common in young people. Almost 21 percent of U.S. children and adolescents have a diagnosable mental health or addictive disorder that affects their ability to function. In any given year, 5 percent to 9 percent of youths ages 9-17 have a serious emotional disturbance that causes substantial impairment in how they function at home, at school, or in the community. Adolescents face a greater risk than adults of developing drug or alcohol use problems; 7.6 percent of adolescents ages 12-17 have met the criteria for dependence on and/or abuse of illicit drugs or alcohol. Mental health problems in adolescents often increase their use of substances such as alcohol, marijuana, and other drugs.

Higher Risk Of Developing Mental Health Problems

Some children and adolescents have a higher risk of developing mental health or substance use problems than others. Children and adolescents whose family members are living with conditions such as depression or other mental health disorders may have a higher risk of developing similar conditions. Youths with developmental disabilities and chronic medical conditions also can have a co-occurring mental health condition or can develop a substance use problem. For example, youths with asthma are at higher risk of developing depression than those who do not have asthma. Adolescents who are questioning their sexual identity or becoming aware of the possibility that they may be gay, lesbian, bisexual, or transgender can be at high risk for certain mental health disorders and misuse of substances. Children and adolescents in the juvenile justice system-especially girls-have been found to have a very high incidence of mental health and substance abuse disorders.

Factors That Can Influence The Risk Of Mental Health

Experiences and environments can increase or decrease the risk of mental health and substance use problems in children and adolescents. Protective factors such as family stability, supportive and nurturing relationships, a strong community, and faith organizations can help prevent certain kinds of problems from developing in children and adolescents. These protective factors also can be a source of support that helps children and adolescents cope with mental health and substance use problems if such problems develop.

Stress and psychological trauma are among a number of environmental risk factors that can contribute to the development of mental health or substance use problems in children and adolescents and also can increase the severity of such problems. Psychological trauma occurs when a youth experiences an intense event that threatens or causes harm to his or her emotional and physical well-being. A range of physiological and psychological behaviors can provide signs that the youth is having difficulty dealing with a traumatic event. However, these reactions are the body's normal response when confronted by danger. Some children and adolescents who have experienced a traumatic event will have longer lasting reactions that can interfere with their physical and emotional health, such as:

  • Children and adolescents in families that have experienced significant losses may face greater challenges to healthy development than those without such losses.
  • Children and adolescents from poor families have increased rates of developmental problems, stress, and uncertainty, which-along with other factors associated with poverty-can trigger behavioral health problems.
  • Psychological trauma can trigger mental health and substance use problems. Children and adolescents who have been abused or neglected are at a higher risk of having mental health or substance use problems.
  • Children and adolescents who were exposed to chronic violence at home or in their communities or who experienced a natural disaster or school violence are at heightened risk for mental health or substance use problems.

The Value Of Early Identification

Caregivers are usually the first to recognize early signs of problems in their children. Medical providers, teachers, or direct care workers in children's programs also are well positioned to improve the identification of mental health and substance use problems among the children and adolescents they serve. Just as schools screen for vision and hearing problems before such problems interfere with learning, service providers can develop early identification programs for mental health and substance use problems.

As children grow older, events in their lives may put them at risk for various problems. For children and adolescents who show clear signs of a mental health or substance use problem, a discrete identification process may not be necessary; instead, these youths can be referred directly for an assessment.


An assessment is conducted by a qualified, experienced mental health or substance abuse professional who gathers more information about the youth to determine whether an identified possible condition is, in fact, present. In addition to speaking with or observing the youth, the professional also should talk to parents or caregivers and-with the consent of parents or caregivers-to teachers or others who know the youth well. This step may involve determining whether a youth meets specific, defined criteria for diagnosis according to a formal classification system in the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) or the Diagnostic Classification of Mental Health and Developmental Disorders of Infancy and Early Childhood (DC:0-3R).

The professional also will collect information that is helpful in working with the child or adolescent and his or her family to develop a plan to address the problem. Because no screening or identification process is perfect, some children and adolescents may be incorrectly found to not have a mental health or substance use problem-when, in fact, they actually have one; or they incorrectly may be found to have a mental health or substance use problem when, in fact, they actually do not have one.

Intervention And/Or Treatment

The goal of identifying children and adolescents with a high likelihood of having mental health and substance use problems is to provide an appropriate intervention or to connect the youths and their families with assessment and treatment resources. Even when an organization can offer an intervention, it must be prepared for the possibility that a youth's problem may warrant additional, different, or more specialized services.

Methods To Identify Adolescents Who May Have Mental Illness

People who are not mental health or substance abuse professionals can employ two basic methods to identify children and adolescents who may have a mental health or substance use problem:

  • Become familiar with signs of mental health and substance use problems.
  • Administer a scientifically validated screening tool.

Become Familiar With Signs Of Mental Illness

Often, a child's or adolescent's behavior or appearance can provide signs of a mental health or substance use problem. These signs warrant action by caregivers and adults who work with the youth and can reliably identify the indicators so that the problem is assessed further and the child or adolescent has the opportunity to receive appropriate treatment. Materials are available to help educate adults about these signs.

Signs of some problems-such as depression, bulimia, or early stages of substance use-either may be actively concealed from adults or may not be readily apparent. Research has shown that these types of problems are difficult for caregivers and other adults to identify. The National Institute of Mental Health (NIMH) and the Substance Abuse and Mental Health Services Administration (SAMHSA) sponsored a research group of scientists and physicians to identify signs that indicate the need to take action and address mental health conditions in children and adolescents.

Higher risk populations can be identified in a number of ways, and common examples of their attributes are as follows:

  • Behavior or functioning. Children and adolescents may demonstrate disciplinary problems; declining academic performance; or a marked change in behavior, mood, or functioning. However, some behavior signs are subtle and easily missed.
  • Illnesses or disabilities. Children and adolescents with certain health problems are at higher risk for depression and other mental health problems. Children and adolescents serving as caretakers for ill or disabled parents or caregivers also are at high risk.
  • Environmental stress. Children and adolescents living in a community with a high rate of poverty or violence are at increased risk of being identified with problems such as substance use or suicide, as compared to children and adolescents in other communities.
  • High-risk life situations. Children and adolescents-particularly those who were prenatally exposed to drugs and alcohol-who come to the attention of child welfare systems or who are in homeless or domestic violence shelters are at high risk for mental health and substance use problems. Children or adolescents involved with the juvenile justice system also are associated with a much higher risk of mental health and substance use problems than children and adolescents in the general population.
  • Stressful events. Stressful events or transitions that are the result of becoming homeless or entering into the child welfare system or juvenile detention involve significant losses and create considerable uncertainty for children and adolescents. Already vulnerable, these youths become even more so. State agencies and programs caring for these children and adolescents not only must safeguard the individual from harming himself or herself but also must ensure that the youth does not harm others. Screening for high-risk conditions as part of the intake process can help these agencies make initial placements and arrangements that are safe for the youth and others. Such screenings also assist in prioritizing assessments by a professional to address ongoing service and placement needs.
  • Traumatic events. Children and adolescents not otherwise at risk may be exposed to an incident of violence or a natural disaster that warrants an effort to identify those who need assistance.
  • Age groups. Certain ages or developmental stages might be prioritized for identification because of the high value of identifying problems or the low likelihood that problems will be identified elsewhere. For example, screening preschool children present an early opportunity for intervention and has great value in preventing a problem or minimizing its impact on the child's future school performance and overall functioning. Screening teens in high school-a time when they no longer may see a primary care physician on a regular basis-has the potential to identify problems less likely to be identified elsewhere. Natural but stressful events associated with specific ages, such as the transition from elementary to middle school, also present potentially useful points of intervention.
  • Sexual orientation. Children and adolescents questioning their sexual orientation or gender identity and those who identify as gay, lesbian, bisexual, transgender, queer, intersex, or two-spirit may have an elevated risk of mental health and substance use problems.

Administer A Scientifically Validated Screening Tool

The specific questions (items) included in a validated screening tool were tested on a large number of youths and were found to most accurately identify children and adolescents with a high likelihood of having mental health or substance use problems. Because different conditions are prone to arise at different stages of development or manifest differently at different ages, screening tools are designed for specific age ranges. Different tools or versions of a tool have been designed and tested to identify different conditions and to be answered by different informants. Informants can be physicians, parents or other caregivers, teachers, or other child service providers who are able to observe the youth; the informant also can be the child or adolescent if he or she is able to understand and answer the questions.

A number of studies have shown that such screening tools are better than the interviewing process used by primary care physicians or a clinical assessment conducted by mental health clinicians at identifying children and adolescents with mental health and substance use problems. The research results for the tested tools indicate the rate and type of problems found in different populations. Screening tools are the best brief method available for personnel who are not mental health or substance abuse professionals to identify children and adolescents at risk of mental health and substance use problems; but, like any medical test, no screening tool is correct all of the time.

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