Treatment response to supplemental nutrients for ADHD is independent of diet quality: the MADDY Study RCT

The 8-week Micronutrients for ADHD in Youth (MADDY) randomized controlled trial (N = 126, age 6-12) of broad-spectrum multinutrients for ADHD with emotional dysregulation found 3 times as many responders with multinutrients (54%) compared to placebo (18%) by Clinical Global Impression-Improvement (CGI-I). Our primary aim for this analysis tests the hypothesis that those with poor overall diet quality at baseline benefit more. The second aim is to explore whether specific components of diet quality moderate treatment response.

124 children (69 multinutrients, 55 placebo) had diet quality assessed using the Healthy Eating Index-2015 (HEI-2015). For each potential moderator, the outcome CGI-I at week 8 (RCT-end), was modeled two ways: (1) as a dichotomous variable: responder/non-responder, with responders defined by a rating of 1 or 2 'very much' or 'much improved,' all else equals non-responder using logistic regression, and (2) as a dimensional improvement outcome from 1 = very much improved to 7 = very much worse, using linear regression.

HEI-2015 total score did not moderate treatment response [odds ratio = 1.00 (95% CI: 0.90,1.10), p = 0.984] or improvement [β = -0.01 (95% CI: -0.06,0.04), p = 0.648]. However, total vegetable intake moderated level of improvement in exploratory analysis [β = -0.48 (95% CI: -0.82, -0.13), p = 0.007]: those with higher baseline vegetable intake showed greater benefit from multinutrients compared to placebo.

Multinutrients may benefit children with ADHD and irritability regardless of overall diet quality. The finding that higher baseline vegetable intake may improve response to multinutrients deserves further exploration, including dietary effect on gut microbiota and absorption of multinutrients and parental factors.