Attention-deficit hyperactivity disorder (ADHD) is one of the most common mental disorders in adolescents, and a full syndrome diagnosis requires a combination of persistent symptoms. In a multicentre cross-sectional study from Italy using a non-clinical sample from a secondary school comprising 440 adolescents, published in this issue of BJPsych Open, Gostoli et al examined whether unhealthy lifestyle habits are linked to both clinical manifestation of ADHD and subclinical symptomatology. In line with the literature, the authors demonstrate an association between clinical ADHD diagnosis, unhealthy lifestyle behaviours and psychosocial impairments. Modifiable, adverse lifestyle behaviours are also prevalent in subclinical ADHD manifestations. This observation may be important for child and adolescent psychiatry when considering targeted health promotion approaches that delay or prevent progression from subclinical to clinical ADHD. In this article, we discuss from a clinical perspective the putative relevance of addressing subclinical ADHD symptoms in the context of the existing literature.