The purpose of this study is to investigate the effectiveness of parent training in the treatment of ADHD in young children (ages 3-7) referred to Danish child mental health services. Medication is not recommended as first-line treatment for young children with ADHD. Parent training is recommended, but has not been formally introduced or established in Denmark. The study will investigate the effectiveness of a parent training programme specifically developed to target ADHD symptoms in young children; The New Forest Parenting Programme, against Treatment as Usual for children diagnosed with ADHD at two different child mental health clinics in Denmark.

Description: A study to: 1) Address the need for non-pharmacological treatment in young children with ADHD and 2) Address the need for the development of evidence-based psychosocial treatment interventions in Danish child mental health services, through the implementation of the New Forest Parenting Programme (NFPP).

Rationale: ADHD is a neuro-developmental disorder with symptoms frequently occurring in early childhood. ADHD is associated with long-term personal, psychosocial sequalae. ADHD presents a considerable societal cost burden, both for mental health services, but also in areas such as education, employment, the criminal justice system. Pharmacological treatment of preschool ADHD is not recommended as first-line treatment, due to a number of reasons, including lack of evidence for efficacy, parental concerns, side effects on growth rates, and the unknown long-term implications for the developing brain. Effective psychosocial treatments for ADHD are therefore of central public priority generally, and for child mental health services, specifically. Currently, psychosocial interventions for ADHD in pre-school children in Danish Child and Adolescent Mental Health Services (CAMHS) are not well described or systematically developed. There is a pressing need to develop evidence-based psycho-social treatments for young children with ADHD in Danish CAMHS.

Design: The study will be a randomised controlled multi-centre effectiveness trial comparing NFPP intervention to a Treatment as Usual control group. The trial will recruit 200 preschool children (aged 3-6) with a diagnosis of ADHD from two Danish outpatient child mental health service sites. Participants will be randomised to either 1) NFPP over a period of 8 weeks or 2) a control group receiving Treatment as Usual (TAU). Outcome: The primary outcome measure will be child ADHD symptoms. Secondary outcomes include parental wellbeing, child quality of life, parent-child interactions. Measures will be collected at three time points to track changes in outcome: T1: Before start of intervention or TAU condition. T2: Directly after the intervention or TAU and T3: 6 month follow-up after T1 for both arms of the trial. The study will perform exploratory moderator and mediator analyses.

Expertise: The study receives external consultation from an international expert team for the planning, execution, NFPP training and supervision. The team consists of research and clinical experts in the treatment and evaluation of interventions for preschool ADHD.

Inclusion Criteria:

1. A clinical diagnosis of ADHD, as measured by the DAWBA
2. Participants first language must be Danish

Exclusion Criteria:

1. Children with intellectual disabilities (i.e. IQ < 70), Autism Spectrum Disorders.
2. Severe parental psychiatric disorder
3. Severe social adversity, as defined by social services involvement due to suspicions of or detected neglect.
4. Child receiving medication or other treatment for ADHD symptoms