Behavioural interventions refer to interventions which are directed at improving an individual’s conduct using reinforcement and social learning principles. This includes increasing desired behaviours and decreasing undesired behaviours. Among these treatments are classical contingency management (1), behaviour therapy (2) and cognitive behavioural therapy (3).

Not all studies investigating these interventions had blinded measures (e.g. symptom rating by an independent researcher) as most used non-blinded measures (e.g. parent symptom rating). This makes evidence more difficult to interpret. When blinded vs. non-blinded measures are taken into account, behavioural intervention can not be supported for the treatment of core ADHD symptoms. However, behavioural interventions did influence parenting effectively making behavioural interventions a form of parent training.

Improving parental knowledge about ADHD may be necessary for subsequent therapeutic interventions. Enhanced knowledge increases the likelihood of engagement in treatment. However, it is not clear whether behavioural interventions improve parental knowledge about ADHD.

Improving parents’ behaviour towards their children with ADHD may improve child behaviour and may improve the quality of the parent-child relationship. Behavioural interventions appear to improve parenting behaviour and reduce child oppositional behaviour. This may lead to increased engagement and cooperation from the child towards the parent and this may improve the parent-child relationships, although this is not entirely clear.

Parent training may not reduce core ADHD symptoms but the interventions change parental perceptions of their child’s behaviour and this can be important as well. Conduct problems are very common in ADHD and behavioural interventions may reduce behavioural problems. However, there is less evidence that behavioural interventions lead to improved emotional functioning in children with ADHD.

Children with ADHD often have impairments in social and academic functioning due to their ADHD symptoms. Behavioural interventions may benefit social skills or academic functioning, especially when an academic or organisational skills component delivered at school is included in the treatment.

It is not entirely clear what the active components of behavioural interventions are. The components should thus not be used in isolation. ADHD-specific programmes are not necessarily superior to generic programmes. The effects of behavioural interventions do not vary across treatment setting and delivery structure although it is important to consider patient preferences and cost of delivery to minimize patient drop-out. A good therapist is important for the delivery of behavioural interventions although evidence for this is limited. The therapist needs to be motivated and deliver the treatment as intended.

It may be useful to involve both parents as this may increase the consistency of the implementation of strategies and shared understanding of ADHD. This, in turn, may lead to better outcomes. However, there is limited evidence to the added value of using both parents.

Behavioural interventions may only need to be used when parents have clear parenting deficits or difficulties as the intervention provides parents with enhanced strategies to deal with a child with ADHD. However, there is no evidence that improvements only occur in families with low pre-existing parenting skills or deficits.

Patient and parent preferences should be taken into account when planning behavioural interventions. However, some preferences may be maladaptive in the case of parental psychopathology (e.g. depression) and it is thus also important to motivate and engage parents. Most parents prefer individual treatment over group-based treatment for ADHD.

Parents need to engage with behavioural parent training for it to be effective but there are several barriers to engagement:

• Situational factors (e.g. transport; timing)
• Psychological factors (e.g. fear; stigma)
• Lack of awareness or unavailability of programmes.
• Issues with poor interagency collaboration.

Enhancing parental motivation to change parenting practices and providing an intervention that addressed the parents’ own needs is important in overcoming these barriers.

The effects of behavioural interventions are reduced by high levels of ADHD in mothers. Parents at risk for ADHD had difficulty maintaining treatment effects in the long-term. Self-efficacy is also important for treatment effects. Mild to moderate parental psychopathology may reduce the effectiveness of the treatment. However, other variables (e.g. intellectual ability) have not been investigated.

There is no evidence that behavioural interventions may exacerbate existing martial conflict or enhance the burden on stressed parents. However, clinicians should mention that family dynamics may be altered by participation.

It is unclear whether severity of ADHD influences the effectiveness of behavioural interventions. The presence of conduct disorder reduces the impact of the intervention while comorbidity with anxiety may make the intervention more effective. Thus, behavioural interventions can be used irrespective of the severity of the symptoms and while comorbidity may alter the effects, the effects will not be iatrogenic.

There is no evidence that early intervention with behavioural interventions reduces the long-term risk of ADHD or associated comorbid disorders. However, interventions should be offered as early as possible as ADHD symptoms may worsen if nothing happens. Thus, early intervention does have special value.

Behavioural interventions often show limited generalizability. This may be due to the limited setting in which they are delivered. Adding school-based and child-focused interventions may help to enhance generalization to school settings. However, there is limited evidence for combining child-focused problem-solving treatment with parent training. There is also no evidence to support the efficacy of working memory training or cognitive training or the combination of behavioural and cognitive or neurofeedback interventions.

Behavioural interventions may need to be combined with treatment for parents’ mental disorders as this is beneficial to parents. However, there is no clear evidence that this influences the effectiveness of behavioural interventions or impact outcomes in children. The exception to this is treatment of parental depression as depression does negatively impact child outcomes.