The fourth revision of the Diagnostic and Statistical Manual (DSM-IV-TR) (now replaced by DSM-5) stated that a person must exhibit four out of the eight signs and symptoms to meet the diagnostic threshold for<unk> . These symptoms include: * Often loses temper * Is often touchy or easily annoyed * Is often angry and resentful * Often argues with authority figures or, for children and adolescents, with adults * Often actively defies or refuses to comply with requests from authority figures or with rules * Often deliberately annoys others * Often blames others for his or her mistakes or misbehavior * Has been spiteful or vindictive at least twice within the past six months These behaviors are mostly directed towards an authority figure such as a teacher or a parent. Although these behaviors can be typical among siblings, they must be observed with individuals other than siblings for an<unk>  diagnosis. Children with<unk>  can be verbally aggressive. However, they do not display physical aggressiveness, a behaviour observed in conduct disorder. Furthermore, they must be perpetuated for longer than six months and must be considered beyond a normal child's age, gender and culture to fit the diagnosis. For children under five years of age, they occur on most days over a period of six months. For children over five years of age they occur at least once a week for at least six months. It is possible to observe these symptoms in only one setting, most commonly home. Thus the severity would be mild. If it is observed in two settings then it is characterized as moderate and if the symptoms are observed in three or more settings then it is considered severe. These patterns of behaviour result in impairment at school or other social venues. Etiology There is no specific element that has yet been identified as directly causing<unk> . Researchers looking precisely at the etiological factors linked with<unk>  are limited. The literature often examines common risk factors linked with all disruptive behaviors, rather than specifically about<unk> . Symptoms of<unk>  are also often believed to be the same as CD even though the disorders have their own respective set of symptoms. When looking at disruptive behaviours such as<unk> , research has shown that the causes of behaviors are multifactorial. However, disruptive behaviours have been identified as being mostly due either to biological or environmental factors. Genetic influences Research indicates that parents pass on a tendency for externalizing disorders to their children that may be displayed in multiple ways, such as inattention, hyperactivity, or<unk>  and conduct problems. Research has also shown that there is a genetic overlap between<unk>  and other externalizing disorders. Heritability can vary by age, age of onset, and other factors. Adoption and twin studies indicate that 50% or more of the variance causing antisocial behavior is attributable to heredity for both males and females.<unk>  also tends to occur in families with a history of ADHD, substance use disorders, or mood disorders, suggesting that a vulnerability to develop<unk>  may be inherited. A difficult temperament, impulsivity, and a tendency to seek rewards can also increase the risk of developing<unk> . New studies into gene variants have also identified possible gene-environment (G x E) interactions, specifically in the development of conduct problems. A variant of the gene that encodes the neurotransmitter metabolizing enzyme monoamine oxidase-A (MAOA), which relates to neural systems involved in aggression, plays a key role in regulating behavior following threatening events. Brain imaging studies show patterns of arousal in areas of the brain that are associated with aggression in response to emotion-provoking stimuli. Prenatal factors and birth complications Many pregnancy and birth problems are related to the development of conduct problems. Malnutrition, specifically protein deficiency, lead poisoning or exposure to lead, and mother's use of alcohol or other substances during pregnancy may increase the risk of developing<unk> . In numerous research, substance use prior to birth has also been associated with developing disruptive behaviors such as<unk> . Although pregnancy and birth factors are correlated with<unk> , strong evidence of direct biological causation is lacking. Neurobiological factors Deficits and injuries to certain areas of the brain can lead to serious behavioural problems in children. Brain imaging studies have suggested that children with<unk>  may have hypofunction in the part of the brain responsible for reasoning, judgment, and impulse control. Children with<unk>  are thought to have an overactive behavioral activation system (BAS), and an underactive behavioural inhibition system (BIS). The BAS stimulates behavior in response to signals of reward or non-punishment. The BIS produces anxiety and inhibits ongoing behavior in the presence of novel events, innate fear stimuli, and signals of non-reward or punishment. Neuroimaging studies have also identified structural and functional brain abnormalities in several brain regions in youths with conduct disorders. These brain regions are the amygdala, prefrontal cortex, anterior cingulate, and insula, as well as interconnected regions. Social-cognitive factors As many as 40 percent of boys and 25 percent of girls with persistent conduct problems display significant social-cognitive impairments. Some of these deficits include immature forms of thinking (such as egocentrism), failure to use verbal mediators to regulate his or her behavior, and cognitive distortions, such as interpreting a neutral event as an intentional hostile act. Children with<unk>  have difficulty controlling their emotions or behaviors. In fact, students with<unk>  have limited social knowledge that is based only on individual experiences, which shapes how they process information and solve problems cognitively. This information can be linked with the social information processing model (SIP) that describes how children process information to respond appropriately or inappropriately in social settings. This model explains that children will go through five stages before displaying behaviors: encoding, mental representations, response accessing, evaluation, and enactment. However, children with<unk>  have cognitive distortions and impaired cognitive processes. This will therefore directly impact their interactions and relationship negatively. It has been shown that social and cognitive impairments result in negative peer relationships, loss of friendship, and an interruption in socially engaging in activities. Children learn through observational learning and social learning. Therefore, observations of models have a direct impact and greatly influence children's behaviors and decision-making processes. Children often learn through modeling behavior. Modeling can act as a powerful tool to modify children's cognition and behaviors. Environmental factors Negative parenting practices and parent–child conflict may lead to antisocial behavior, but they may also be a reaction to the<unk>  and aggressive behaviors of children. Factors such as a family history of mental illnesses and/or substance use disorders as well as a dysfunctional family and inconsistent discipline by a parent or guardian can lead to the development of behavior disorders. Parenting practices not providing adequate or appropriate adjustment to situations as well as a high ratio of conflicting events within a family are causal factors of risk for developing<unk> . Insecure parent–child attachments can also contribute to<unk> . Often little internalization of parent and societal standards exists in children with conduct problems. These weak bonds with their parents may lead children to associate with delinquency and substance use. Family instability and stress can also contribute to the development of<unk> . Although the association between family factors and conduct problems is well established, the nature of this association and the possible causal role of family factors continues to be debated. School is also a significant environmental context besides family that strongly influences a child's maladaptive behaviours. Studies indicate that child and adolescent externalising disorders like<unk>  are strongly linked to peer network and teacher response. Children with<unk>  present hostile and<unk>  behaviour toward authority including teachers which makes teachers less tolerant toward<unk>  children. The way in which a teacher handles disruptive behaviour has a significant influence on the behaviour of children with<unk> . Negative relationships from the socialising influences and support network of teachers and peers increases the risk of<unk>  behaviour. This is because the child consequently gets affiliated with<unk>  peers that reinforce antisocial behaviour and delinquency. Due to the significant influence of teachers in managing disruptive behaviours, teacher training is a recommended intervention to change the disruptive behaviour of<unk>  children. In a number of studies, low socioeconomic status has also been associated with disruptive behaviors such as<unk> . Other social factors such as neglect, abuse, parents that are not involved, and lack of supervision can also contribute to<unk> . Externalizing problems are reported to be more frequent among minority-status youth, a finding that is likely related to economic hardship, limited employment opportunities, and living in high-risk urban neighborhoods. Studies have also found that the state of being exposed to violence was a contribution factor for externalizing behaviors to occur.
Oppositional defiant disorder
Attention deficit hyperactivity disorder
Conduct disorder
Tourette syndrome
Personality development disorder
Motivational deficiency disorder
Obsessive–compulsive personality disorder
Obsessive–compulsive disorder