PURPOSE: Having a neurodevelopmental disorder (NDD) increases the risk of mental health problems and lower participation. We investigated the trajectories of mental health problems and participation in adolescents with NDD and compared these with trajectories for peers without NDD. In addition, the relationship between participation, mental health (well-being), and mental health problems were investigated.

MATERIALS AND METHODS: Data from a Swedish longitudinal survey study (LoRDIA) was used and adolescents with and without self-reported NDD were followed from 12/13 to 17 years, in three waves. Mental health problems were measured using the Strength and Difficulties Questionnaire, and well-being was measured with the Mental Health Continuum short form.

RESULTS: Adolescents with NDD experience more mental health problems than adolescents without NDD. Hyperactivity, a key feature of NDD, remains stable, while emotional problems and psychosomatic complaints, increase over time for girls, independent of NDD. Participation is stable over time but is more related to well-being than to NDD or mental health problems.

CONCLUSIONS: Gender is an important factor with girls exhibiting more problems. Mental health explains more of the variation in participation than mental health problems and NDD. Probably participation intervention can enhance mental health which may protect from mental health problems.

Implications for rehabilitation

• Mental health, i.e., emotional-, social-, and psychological well-being is more strongly related to participation and to reduced levels of mental health problems than having an NDD or not, thus assessing mental health separately from measuring NDD is important.
• Interventions focusing on participation may lead to higher mental health and having high mental health (flourishing) may facilitate participation.
• Girls with self-reported NDD seem to have a higher burden of mental health problems, especially if they also are languishing, i.e., having low mental health, therefore a strong focus on this group is needed both in research and clinical practice.
• Half of all adolescents are flourishing, independently of NDD or not, even if they are experiencing some symptoms of mental health problems, adolescents with NDD who are also languishing, have much higher ratings of mental health problems.