The paper presents the results of a research study that aimed to investigate if intelligence influences the behavioural progress of children with ADHD attending a complex experiential psychotherapy plan that combined metaphorical scenarios with special groups of professional optimisation organised for the teachers of these children. The research sample included 40 children diagnosed with ADHD, combined type. Psychological assessment test battery used for selection included: anamnesis, Semi-structured Clinical Interview for Children and Adolescents, ADHD Rating Scale, completed before treatment and after treatment, Behavioural Coding Sheet completed before treatment and after treatment, and Raven's Colour Progressive Matrices CPM. We have conducted the MANOVA for five dependent variables (off task, fidget, vocal, play, out seat) and three independent variables (optimization groups for teachers, child experiential psychotherapy and IQ). Noticing that the IQ has an influence on vocal, play and out seat, we have conducted One-Way ANOVA procedure to test where the difference comes from.