Table 5.

Candidate neurophysiological biomarkers investigated in at least two studies, with at least one positive finding, in relation to attention‐deficit/hyperactivity disorder (ADHD)

Biomarker	Number of significant effects	Number of non‐significant effects	Direction	Rate of replication (%)
MEG/EEG measures
N2 amplitude	4	0	Four increased	100
Contingent negative variation (CNV) amplitude	2	0	Two increased	100
Mismatch negativity (MMN) latency	2	0	Two increased	100
Gamma coherence	2	0	Two decreased	100
P3 amplitude	6	3	Six decreased	67
Mismatch negativity (MMN) amplitude	2	1	Two increased	67
Alpha clustering coefficient	2	1	Two decreased	67
Alpha path length	2	1	Two decreased	66
Delta power	10	2	Six increased, four decreased	50
Alpha coherence	2	0	One increased, one decreased	50
Theta/beta ratio	5	7	Five increased	42
Alpha power	13	6	Five increased, eight decreased	42
Theta power	5	9	Five increased	36
P3 latency	1	2	One increased	33
Gamma power	2	4	Two decreased	33
Alpha peak frequency	1	2	One decreased	33
Alpha asymmetry	2	4	Two increased	33
Theta coherence	3	0	One increased, two decreased	33
Beta power	9	11	Four increased, five decreased	25
Actigraphy
Activity level	2	0	Increased	100
Oculomotor measures and visual attention
Exploration of social information	1	2	One increased	33
Visual attention orienting	3	5	Two increased, one decreased	25
Pupillometry
Pupil diameter changes	1	1	One decreased	50

MEG – magnetoencephalography, EEG – electroencephalography