The studies published in the special issue contribute to further our understanding on the links between Attention-Deficit/Hyperactivity Disorder (ADHD) and asthma (Sun et al., ); the relationship between anorexia nervosa and inflammatory bowel diseases (Larsen et al., ); the association of retinal vascular calibre with regional brain structure in adolescent bipolar disorder (Mio et al., ); the role of integrated care for child and adolescent health (Fazel et al., ); the acceptability, feasibility and impact of a drop-in centre to address emotional and behavioural problems in children with chronic physical conditions (Bennett et al., ); the efficacy of group-based Acceptance and Commitment Therapy for adolescents with multiple functional somatic syndromes (Kallesøe et al., ); and the evidence on physical exercise interventions in child and adolescent mental health (Carney & Firth, ). Should this putative d factor be confirmed, it would have substantial implications not only from a theoretical or even philosophical standpoint, but also from a practical perspective, providing a strong rationale for the integrated care for children and adolescents advocated in this issue by Fazel et al. () and Bennett et al. (). ...this special issue of JCPP Advances projects us in an important future development of our discipline. A drop‐in centre for treating mental health problems in children with chronic illness: