Table 2. Non-pharmacological interventions—efficacy with respect to ADHD core manifestations.

Interventions	Effect strength. OR [95% CI]		Remarks
	Unblinded	Blinded
Dietetic interventions
Elimination diet (32)	1.48 [0.35; 2.61]	0.51 [−0.02; 1.04]	Statistically insignificant effect in blinded assessment
No artificial coloring (32)	0.32 [0.06; 0.58]	0.42 [0.13; 0.70]	Statistically significant. moderately strong effect in selected cohorts in blinded assessment
Unsaturated fatty acid supplementation (32)	0.21 [0.05; 0.36]	0.16 [0.01; 0.31]	Statistically significant but clinically irrelevant effect in blinded assessment
Psychological interventions
Cognitive training (32, 35)	0.64 [0.33; 0.95] 0.37 [0.09; 0.66]	0.24 [−0.24; 0.72] 0.20 [0.01; 0.40]	Meta-analysis 1: No statistically significant effect in blinded assessment (32) Meta-analysis 2: Improvement of working memory in blinded assessment (verbal: 0.52 [0.24; 0.80]; visual: 0.47 [0.23; 0.70]) and small but significant effect on ADHD core manifestations (35)
Neurofeedback (32, 34)	0.59 [0.31; 0.87]	0.29 [−0.02; 0.62]	In blinded assessment, no statistically significant effect when all studies are included (32); nonetheless, an exploratory secondary analysis (34) reveals a moderately strong, statistically significant effect with the use of a standardized neurofeedback protocol (0.36 [0.04; 0.69])
Behavioral therapy (32, 33)	0.40 [0.20; 0.60]	0.02 [−0.30; 0.34]	In blinded assessment, no statistically significant reduction of ADHD core manifestations (32), but (33) there is significant improvement in positive parenting behavior (0.63 [0.47; 0.7]), reduction in negative parenting behavior (0.43 [0.24; 0.62]), and reduction of abnormal conduct (0.31 [0.05; 0.57])

ADHD. attention-deficit/hyperactivity disorder; OR. odds ratio; CI. confidence interval