Conduct disorder (CD) is a mental disorder diagnosed in childhood or adolescence that presents itself through a repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate norms are violated. These behaviors are often referred to as antisocial behaviors. Conduct disorder (CD) is often seen as the precursor to antisocial personality disorder, which is per definition not diagnosed until the individual is 18 years old. Conduct disorder is estimated to affect 51.1 million people globally as of 2013.

Signs and Symptoms

Figure 1. Conduct disorder is characterized by aggressive and destructive behavior. It is diagnosed in childhood or adolescence and is often seen as a precursor to the adult-diagnosis of antisocial personality disorder. It affects more boys than girls.

According to DSM-5 criteria for conduct disorder (CD), there are four categories that could be present in the child’s behavior: aggression to people and animals, destruction of property, deceitfulness or theft, and serious violation of rules.

One of the symptoms of CD is a lower level of fear. Research performed on the impact of toddlers exposed to fear and distress shows that negative emotionality (fear) predicts toddlers’ empathy-related response to distress. The findings support that if a caregiver is able to respond to infant cues, the toddler has a better ability to respond to fear and distress. If a child does not learn how to handle fear or distress, the child will be more likely to lash out at other children. If the caregiver is able to provide therapeutic intervention teaching children at risk better empathy skills, the child will have a lower incident level of conduct disorder.

Increased instances of violent and antisocial behavior are also associated with the condition; examples may range from pushing, hitting, and biting when the child is young, progressing towards beating and inflicted cruelty as the child becomes older.

Conduct disorder can present with limited prosocial emotions, lack of remorse or guilt, lack of empathy, lack of concern for performance, and shallow or deficient affect. Symptoms vary by individual, but the four main groups of symptoms are described below.

• aggression to people and animals
  • often bullies, threatens, or intimidates others
  • often initiates physical fights
  • has used a weapon that can cause serious physical harm to others (e.g., a bat, brick, broken bottle, knife, gun)
  • has been physically cruel to people
  • has been physically cruel to animals
  • has stolen while confronting a victim (e.g., mugging, purse snatching, extortion, or armed robbery)
  • has forced someone into sexual activity (rape or molestation)
• destruction of property
  • has deliberately engaged in fire setting with the intention of causing serious damage
  • has deliberately destroyed others’ property (other than by fire setting)
• deceitfulness or theft
  • has broken into someone else’s house, building, or car
  • often lies to obtain goods or favors or to avoid obligations (i.e., cons others)
  • has stolen items of nontrivial value without confronting a victim (e.g., shoplifting, but without breaking and entering; forgery)
• serious violations of rules
  • often stays out at night despite parental prohibitions, beginning before age 13
  • has run away from home overnight at least twice while living in parental or parental surrogate home (or once without returning for a lengthy period)
  • is often truant from school, beginning before age 13

Currently, two possible developmental courses are thought to lead to conduct disorder. The first is known as the childhood-onset type and occurs when conduct disorder symptoms are present before the age of 10. This course is often linked to a more persistent life course and more pervasive behaviors. Specifically, children in this group have greater levels of ADHD symptoms, neuropsychological deficits, more academic problems, increased family dysfunction, and higher likelihood of aggression and violence.

There is debate among professionals regarding the validity and appropriateness of diagnosing young children with conduct disorder. The characteristics of the diagnosis are commonly seen in young children who are referred to mental health professionals. A premature diagnosis made in young children, and thus labeling and stigmatizing an individual, may be inappropriate. It is also argued that some children may not in fact have conduct disorder, but are engaging in developmentally appropriate disruptive behavior.

The second developmental course is known as the adolescent-onset type and occurs when conduct disorder symptoms are present after the age of 10 years. There is also the additional onset-type of “unspecified” when it’s not known whether symptoms began prior to age 10.

In addition to these two courses that are recognized by the DSM-5, there appears to be a relationship among oppositional defiant disorder, conduct disorder, and antisocial personality disorder. Specifically, research has demonstrated continuity in the disorders such that conduct disorder is often diagnosed in children who have been previously diagnosed with oppositional defiant disorder, and most adults with antisocial personality disorder were previously diagnosed with conduct disorder. For example, some research has shown that 90% of children diagnosed with conduct disorder had a previous diagnosis of oppositional defiant disorder. Moreover, both disorders share relevant risk factors and disruptive behaviors, suggesting that oppositional defiant disorder is a developmental precursor and milder variant of conduct disorder. However, this is not to say that this trajectory occurs in all individuals. In fact, only about 25% of children with oppositional defiant disorder will receive a later diagnosis of conduct disorder.

Figure 2. Almost all adolescents who have a substance use disorder have conduct disorder-like traits, but after successful treatment for substance abuse, about half of these adolescents no longer display conduct disorder-like symptoms. Therefore, it is important to exclude a substance-induced cause and instead address the substance use disorder prior to making a psychiatric diagnosis of conduct disorder.

Correspondingly, there is an established link between conduct disorder and the diagnosis of antisocial personality disorder as an adult. In fact, the current diagnostic criteria for antisocial personality disorder requires a conduct disorder diagnosis before the age of 15 if the patient being diagnosed is still under 18 years old. Having a conduct disorder is a risk factor for later diagnosis of antisocial personality disorder. However, again, only 25–40% of youths with conduct disorder will develop antisocial personality disorder. Nonetheless, many of the individuals who do not meet the full criteria for antisocial personality disorder still exhibit a pattern of social and personal impairments or antisocial behaviors. These developmental trajectories suggest the existence of antisocial pathways in certain individuals, which have important implications for both research and treatment.

Epidemiology

As stated before, this disorder is estimated to affect approximately 51 million people globally as of 2013. The percentage of children affected by conduct disorder is estimated to range from one to 10%. However, among incarcerated youth or youth in juvenile detention facilities, rates of conduct disorder are between 23% and 87%.

An epidemiological meta-analysis estimated that the worldwide prevalence of conduct disorder among children and adolescents aged six to 18 years is 3.2% and the prevalence estimate does not vary significantly across countries.

Conduct disorder can have its onset before ten years of age or in adolescence, and children with early onset conduct disorder are at greater risk for persistent difficulties. Current data indicates that the prevalence of conduct disorder is 2%-5% in children between five an 12 years old and 5%-9% in adolescents between 13 and 18 years old. Most studies show that boys are more likely to present with symptoms of conduct disorder than girls. However, this gender difference may vary somewhat across development. In young children under five years age, gender differences are small. This changes in adolescence, where both genders show an increase in the rates of conduct disorder and boys are two to three times more likely to be diagnosed than girls. Conduct disorder prevalence may or may not vary in different races and ethnicities depending on SES, neighborhood, and parenting practices. According to current data, the lifetime prevalence of conduct disorder is 6.9% for Hispanics, 4.9% for Blacks, and 5.0% for Whites. Caucasian children are more likely to be diagnosed with oppositional defiant disorder whereas Black children are more likely to be diagnosed with conduct disorder. Male teens, those from communities of color, and children from low-income families are likely to be diagnosed with severe problems linked to neurological, attention, and conduct functioning.^[1]

Etiology

The etiology of CD is complex and results from an interaction between multiple biological and psychosocial factors.

Biological

• Various studies indicate a moderate degree of heritability for antisocial behavior, impulsivity, temperament, aggression, and insensitivity to punishment.
• Evidence for low levels of plasma dopamine beta-hydroxylase supports the finding of decreased activity of the noradrenergic system in the CD.
• Low levels of 5-Hydroxy Indole acetic acid (5-HIAA) levels in cerebrospinal fluid correlate with aggression and violence in adolescence.
• High testosterone levels are also associated with aggression.

Neurological

• Some studies suggest a correlation between resting frontal brain electrical activity (EEG) and aggression in children.
• Neuropsychological insults to the brain in early life can cause deficits in language, memory, and executive functioning leading to poor judgment and inability to plan and problem solve in crisis situations.
• Developmental delays cause poor social skills, learning disability, and below-average intellectual capacity, thus contributing to difficulties in learning, academic difficulties, low self-esteem, and a tendency for children to engage in disruptive behaviors.
• Any traumatic brain injury, seizures, and neurological damage can contribute to aggression.

Parental and Family

• A home environment that lacks structure and adequate supervision with frequent marital conflicts between parents and inconsistent discipline leads to maladaptive behavior and/or the following:
  • harsh parenting with verbal and physical aggression towards children
  • children exposed to frequent domestic violence
  • the family history of criminality and disruptive behaviors in caregivers
  • substance abuse, particularly alcohol dependence, in parents
  • living in low social, economic conditions with overcrowding and unemployment lead to economic and social stress and a possible lack of adequate parenting.

School

• school environment with large classroom size, increased ratio of children to teachers, lack of positive feedback from teachers
• lack of supportive staff and counseling to address socio-economic difficulties in children
• exposure to increased gang violence in the community

Comorbid Conditions

• Children with a difficult temperament demonstrate poor adaptability and frequent negative emotions.
• Almost one-third of children with ADHD have symptoms of conduct disorder and other central nervous system dysfunction or damage.
• Trauma-related disorders, particularly repeated physical and sexual abuse with maltreatment in children, can lead to a diagnosis of PTSD and other anxiety disorders.
• Mood disorders that include depression and bipolar disorder can be comorbid.
• Developmental disorders can also be present.

In summary, the most important risk factors that predict conduct disorder include impulsiveness, low IQ and low school achievement, inadequate parental supervision, punitive or erratic parental discipline, cold parental attitude, child physical abuse, parental conflict, disrupted families, antisocial parents, large family size, low family income, antisocial peers, high delinquency rate schools, and high-crime neighborhoods. However, for many risk factors, it is not known whether they have causal effects. Cadoret et al. examined children who had a biological family history of antisocial personality disorder who were adopted into either stable or pathologic (unstable, disruptive) homes. They determined the highest incidence of aggression, and conduct disorder occurred in children who had both a family history of antisocial behavior and were placed in disturbed adoptive homes.^[2]

Treatment & Outlook

Assessment and multiple interviews with the family, caregivers, and the child or adolescent are a critical first step and should include as many resources as possible, including educators, social workers, clinical psychologists, and family physicians. Since so many risk factors are involved, effective treatment needs to include a way to prevent or address these issues; this can involve family and social systems-based approaches and begin with educating both the patient and parents/caregivers regarding the disorder, complications, and possible long-term consequences, especially if it continues untreated. CBT skill training has been found to be helpful by teaching patients skills in responding to their anger through problem-solving steps and finding alternative responses. Medication treatment is mainly used for comorbid conditions, such as ADHD, and is not a sole (or main) response to treating CD.^[3]

Sadly, youth diagnosed with conduct disorder have a higher degree of distress and impairment in virtually all domains of living compared to youth with other mental disorders. Many studies have demonstrated the long-term impact of conduct disorder as a developmental precursor of antisocial behavior and criminality. Conduct disorder diagnosed in childhood acts as a strong predictor of many problems in adolescence and adulthood, including mental illness, substance abuse, legal problems, school drop-out, academic issues, and occupational problems. In two longitudinal studies, children with comorbid conduct and depressive disorders had a higher risk of late-onset criminality and antisocial behavior compared to those with only emotional issues.^[4]