Conduct disorders are the most common type of mental and behavioural problem in children and young people. They are characterised by repeated and persistent patterns of antisocial, aggressive or defiant behaviour, much worse than would normally be expected in a child of that age. Types of behaviour include stealing, fighting, vandalism, and harming people or animals.

Younger children often have a type of conduct disorder called “oppositional defiant disorder”. In these children, the antisocial behaviour is less severe and often involves arguing (“opposing”) and disobeying (“defying”) the adults who look after them. In teenagers with conduct disorders, the pattern of behaviour can become more extreme and include:

• aggression towards people or animals
• destruction of property
• persistent lying and theft
• serious violation of rules

Children with conduct disorders often have other mental health problems, particularly attention deficit hyperactivity disorder (ADHD).

These disorders are the most common reason for children being referred to mental health services, with 5% of all children between five and 16 years old diagnosed with the condition.
The proportion of children with conduct disorders increases with age and they are more common in boys than girls. For example, 7% of boys and 3% of girls aged five to 10 years have conduct disorders; in children aged 11 to 16 years, the proportion rises to 8% of boys and 5% of girls.

What causes conduct disorders? It is not yet clear why conduct disorders develop. A prevailing view is that, like many mental health conditions, a combination of environmental and biological factors may be involved.

Possible environmental factors include:

• a “harsh” parenting style
• parental mental health problems such as depression and substance misuse
• parental history, such as the breakup of a marriage
• poverty
• individual factors, such as low achievement
• the presence of other mental health problems

In terms of biology, researchers who looked at the brain structures of teenage boys with conduct disorders have found differences in areas of the brain associated with emotions such as empathy and behaviours such as risk-taking. There may be certain genetic variants that a child inherits that may also make them more prone to develop conduct disorders.

Children and young people diagnosed with conduct disorders often fail at school or college and become socially isolated. In adolescence, they may misuse drugs and alcohol or become involved with the criminal justice system. As adults, this group do badly in terms of education and jobs, are often involved in crime and also have high levels of mental health problems such as antisocial personality disorder.

Several approaches have been developed for children at risk of, or diagnosed with, conduct disorders. In particular, parenting programmes are run by health and social care professionals to help parents improve their children’s behaviour. Treatment for the children themselves includes psychological therapies and sometimes, medication. The treatment of children with conduct disorder can involve many different agencies including health professionals, social services, school and college.

Recognising that a child may be at risk of, or has developed conduct disorder at an early age may help prevent problems later. Conduct disorder is different from the occasional tantrum or “naughtiness” in a child.

The behaviour of a child with conduct disorder may depend on their age. Younger children (aged under 11) may repeatedly argue with, disobey and defy those looking after them.

Older children with conduct disorder may consistently exhibit antisocial behaviour, such as:
• being highly aggressive towards people and animals
• stealing or damaging property
• lying
• fighting
• violating rules

If you are concerned about your child’s behaviour, seek advice from your GP as soon as possible.

NICE has made a number of recommendations about the diagnosis and treatment of conduct disorders. Its key recommendations are outlined below.

Selective Prevention

One of the key messages contained in the NICE guidelines is the importance and usefulness of selective prevention. Selective prevention means identifying individual children with an above average risk of developing a conduct disorder and then providing treatment to try and prevent that from occurring. The rationale being that it is usually easier to prevent a disease than to cure one.

NICE recommend that younger children aged three to seven years should be considered for selective prevention if:

• they are growing up in a poor household
• they are underachieving at school
• there is a history of child abuse or parental conflict
• their parents are separated or divorced
• one or both of the parents has a history of mental health problems and /or substance abuse problems
• one or both parents have come into contact with the criminal justice system

Assessment

NICE recommends that children or young people at risk of developing a conduct disorder or who are suspected of having a conduct disorder are assessed by qualified health or social care professionals.

Initial assessment should involve checking for the following complicating factors:

• a coexisting mental health problem (for example, depression or post-traumatic stress disorder)
• a neurodevelopmental condition (in particular ADHD and autism)
• a learning disability or difficulty
• substance misuse (in older children)

The initial assessment should then be followed by a more comprehensive assessment. This should include asking about and assessing the following:

• core conduct disorder symptoms in younger children (aged under 11) – particularly symptoms associated with oppositional defiant disorder, defined by NICE as “patterns of negativistic, hostile, or defiant behaviour”
• core conduct disorder symptoms in older children (aged over 11) such as aggression to people and animals, destruction of property, deceitfulness or theft, and serious violations of rules” in children aged over 11 years
• current functioning at home, school or college, and with peers
• parenting quality
• history of any past or current mental or physical health problem.