Protective factors have also been identified, and most notably include high IQ, being female, positive social orientations, good coping skills, and supportive family and community relationships.However, a correlation between a particular risk factor and a later developmental outcome (such as conduct disorder) cannot be taken as definitive evidence for a causal link. Co-variation between two variables can arise, for instance, if they represent age-specific expressions of similar underlying genetic factors. There have been studies that found that, although smoking during pregnancy does contribute to increased levels of antisocial behaviour, in mother-fetus pairs that were not genetically related (by virtue of in-vitro fertilisation), no link between smoking during pregnancy and later conduct problems was found. Thus, the distinction between causality and correlation is an important consideration. Learning disabilities
While language impairments are most common, approximately 20-25% of youth with conduct disorder have some type of learning disability. Although the relationship between the disorders is complex, it seems as if learning disabilities result from a combination of ADHD, a history of academic difficulty and failure, and long-standing socialization difficulties with family and peers. However, confounding variables, such as language deficits, SES disadvantage, or neurodevelopmental delay also need to be considered in this relationship, as they could help explain some of the association between conduct disorder and learning problems. Cognitive factors
In terms of cognitive function, intelligence and cognitive deficits are common amongst youths with conduct disorder, particularly those with early-onset and have intelligence quotients (IQ) one standard deviation below the mean and severe deficits in verbal reasoning and executive function.
As mentioned above, it seems that there is a transactional relationship between substance use and conduct problems, such that aggressive behaviors increase substance use, which leads to increased aggressive behavior.Substance use in conduct disorder can lead to antisocial behavior in adulthood. Schizophrenia
Conduct disorder is a precursor to schizophrenia in a minority of cases, with about 40% of men and 31% of women with schizophrenia meeting criteria for childhood conduct disorder. Cause
While the cause of conduct disorder is complicated by an intricate interplay of biological and environmental factors, identifying underlying mechanisms is crucial for obtaining accurate assessment and implementing effective treatment. These mechanisms serve as the fundamental building blocks on which evidence-based treatments are developed. Despite the complexities, several domains have been implicated in the development of conduct disorder including cognitive variables, neurological factors, intraindividual factors, familial and peer influences, and wider contextual factors. These factors may also vary based on the age of onset, with different variables related to early (e.g., neurodevelopmental basis) and adolescent (e.g., social/peer relationships) onset. Risks
The development of conduct disorder is not immutable or predetermined. A number of interactive risk and protective factors exist that can influence and change outcomes, and in most cases conduct disorder develops due to an interaction and gradual accumulation of risk factors. In addition to the risk factors identified under cause, several other variables place youth at increased risk for developing the disorder, including child physical abuse, in-utero alcohol exposure, and maternal smoking during pregnancy.