Parents of 44 children ages 6–17 with a primary diagnosis of ADHD consented to take part in the study. Parents completed the Spanish version of the Swanson, Nolan and Pelham Scale for parents (SNAP-IV) and the Abbreviated Conner's Rating Scales for parents (CPRS-HI) prior to an 11-week chess-training program. We used a paired t-test to compare pre- and post-intervention outcomes, and Cohen-d calculations to measure the magnitude of the effect. The statistical significance was set at p < .05.
Children with ADHD improved in both the SNAP-IV (t = 6.23; degrees of freedom (df) = 41; p < .001) and the CPRS-HI (t = 5.39; df = 33; p < .001). Our results suggest a large effect in decreasing the severity of ADHD as measured by the SNAP-IV (d = 0.85) and the CPRS-HI (d = 0.85). Furthermore, we found a correlation between intelligence quotient and SNAP-IV improvement (p < .05).
The results of our pilot study should be interpreted with caution. This pilot project highlights the importance of carrying out larger studies with a case–control design. If our results are replicated in better designed studies, playing chess could be included within the multimodal treatment of ADHD.