such as separation anxiety disorder or social phobia, are also relatively common. Certain conditions, such as autism, are more common than previously thought. Approximately 1 in 59 children will develop this serious condition (Centers for Disease Control and Prevention, 2020c). Other problems such as eating disorders and schizophrenia are relatively rare in children.
Table 1.2
Note: This table shows the median percentage of youths with each disorder from the following datasets (for 2013–2020): Centers for Disease Control and Prevention, National Comorbidity Survey Replication–Adolescent Supplement, National Health Interview Survey, National Health and Nutrition Examination Survey, National Survey of Children’s Health, National Survey on Drug Use and Health, and the National Youth Risk Behavior Survey.
Comorbidity and Costs
Children’s disorders tend to occur together. Comorbidity refers to the presentation of two or more disorders in the same person at the same time. On average, approximately 40% of children and adolescents with one mental disorder have at least one other condition (Merikangas & He, 2014). Certain disorders show high comorbidity in children and adolescents. For example, 75% of youths with depression also experience an anxiety disorder that interferes with their daily functioning (Cummings, Caporino, & Kendall, 2014). Approximately 50% of young children with ADHD also exhibit conduct problems, such as oppositional and defiant behavior toward parents or other adults (Pliszka, 2015). For many mental health problems, comorbidity is the rule rather than the exception in children.
Psychological disorders negatively affect the lives of children and families. The total cost of child and adolescent mental health care in the United States is approximately $247 billion annually (Centers for Disease Control and Prevention, 2016b). Children with mental health problems need evidence-based interventions, such as counseling and/or medication, to help them manage their symptoms and improve their functioning. Children’s mental health problems can also compromise their caregivers’ well-being, leading to reduced productivity at work and increased tension at home. The cost to communities is also enormous. Societal costs include rehabilitation for youths with conduct problems, drug and alcohol counseling for youths with substance use disorders, and family supervision and reunification services for youths who experience maltreatment. School districts must pay for special education services for children with cognitive, learning, and behavior problems that interfere with their ability to benefit from regular education. Preventing childhood disorders would spare families suffering and save communities money. Unfortunately, prevention remains an underutilized approach to dealing with child and adolescent psychopathology in the United States (Forbes, Rapee, & Krueger, 2020).
Review
Prevalence refers to the percentage of children in a given population with a disorder. Incidence refers to the percentage of new cases of a disorder in a discrete period of time.
Between 13% and 15% of youths experience a psychological disorder each year; 20% of youths experience a disorder before reaching adulthood. The most common disorders in children are ADHD and anxiety disorders.
Approximately 40% of youths with one disorder have another (comorbid) disorder.
What Factors Influence the Prevalence of Childhood Disorders?
Age
The prevalence of mental disorders varies with age. On average, adolescents are more likely than younger children to experience mental health problems. The best data that we have regarding the prevalence of mental health problems in adolescents comes from the results of the National Comorbidity Survey Replication–Adolescent Supplement (Kessler et al., 2012a). The researchers who conducted this study interviewed a nationally representative sample of more than 10,000 adolescents ages 13 to 17. They also administered rating scales to parents to gather additional data on adolescents’ functioning. Results showed that 23.4% of adolescents reported a mental health problem in the past month and 40.3% reported a mental health problem in the previous year. Although most of the problems experienced by adolescents were mild to moderate in severity, the overall prevalence of problems was much higher than in previous studies involving younger children (Kessler et al., 2012b).
The National Comorbidity Survey study also allows us to compare the prevalence of specific disorders across childhood and adolescence (Figure 1.2). Certain disorders are more common among younger children: autism, separation anxiety, and ADHD. However, the prevalence of most disorders increases with age. For example, adolescents are much more likely to experience problems with social phobia, depression, bipolar disorders, and eating disorders than prepubescent children. Problems with alcohol and other drug use also typically emerge in adolescence and are relatively rare among prepubescent children (Merikangas & He, 2014).
Figure 1.2 ■ The Prevalence of Childhood Disorders Varies by Age
Note: In general, adolescents are more likely to experience disorders than younger children. However, some disorders, like autism and separation anxiety disorder, are more common among younger children (Kessler et al., 2012a; Perou et al., 2016).
Gender
The prevalence of psychological disorders also varies across gender. In early childhood, many disorders are more typically seen in boys. For example, boys are 4 times more likely than girls to be diagnosed with autism spectrum disorder and 3 times more likely than girls to be diagnosed with ADHD. Boys are also more likely than girls to show disruptive behavior problems, such as oppositional defiant disorder. The prevalence of other disorders is approximately equal in young boys and girls (Perou et al., 2016).
By adolescence, however, girls are more likely than boys to experience mental health problems (Kessler et al., 2012a). Adolescent boys continue to be at greater risk than adolescent girls for conduct problems and physical aggression. Similarly, adolescent boys are slightly more likely than adolescent girls to develop problems with alcohol and other drugs. However, adolescent girls are 2 to 3 times more likely than adolescent boys to experience problems with depression or anxiety. Furthermore, adolescent girls are 5 to 10 times more likely than adolescent boys to be diagnosed with an eating disorder.
Psychologists have struggled to explain why girls show a dramatic increase in mental health problems during adolescence. Researchers have suggested many causes ranging from biological changes during puberty to unreasonable social–cultural expectations placed on females throughout the lifespan. Recently, however, researchers have identified two particularly important factors: stressful life events and the way girls think about those events.
In one study, researchers followed a large sample of adolescents from late childhood through middle adolescence (J. L. Hamilton, Stange, Abramson, & Alloy, 2015). Most youths reported increased stress during this time period; however, girls were particularly sensitive to interpersonal stressors—that is, stressful events that involved important people or relationships in their lives. For example, girls were especially likely to report difficulties with parents, peers, or romantic partners during their tween and teen years.
Perhaps more importantly, the way girls thought about these interpersonal stressors influenced their mood. For example, adolescents who believed they were responsible for these interpersonal problems (e.g., “It’s my fault my mom is angry with me”) were more likely to experience depression than adolescents who did not blame themselves (e.g., “My mom is just grouchy after working all day”). Similarly, adolescents who tended to overthink these events (e.g., “I wonder why my friends are mad at me? Was it something I said?”) were also more likely to experience problems with depression than girls who did not dwell on these events. These findings suggest that girls’ thoughts about interpersonal problems can greatly determine their well-being (From Science to Practice).