Table 1 Diffusion imaging studies in children with ADHD.

Acer et al., 2017

17

10.55 (2.8)

15

101.3 (12.3)

NA

0

NA

10

10.21 (2.1)

7

108.6 (8.2)

ROI

Increased MD in the deep GM, amygdala, thalamus, substantia nigra, and cerebellum bilaterally. Increased RD in the deep GM, caudate, thalamus, substantia nigra and hippocampus bilaterally. Increased FA in the bilat splenium of the CC

Adisetiyo et al., 2014

22

12.6 (2.8)

15

106.8 (15.6)

ADHD-C: 14

ADHD-I: 8

11

12

27

13.3 (2.6)

12

111.3 (14.7)

TBSS + VBA

Greater WM microstructural complexity in bilat frontal and parietal lobes (including SLF, ACR, superior and posterior CR, PTR, left CING), temporal lobes (ILF, IFOF, PTR), L occipital lobe (SLF, PTR), thalamus, insula, CC, and R IC and EC

Alger et al., 2021

1)ADHD+PAE: 23

2) ADHD-PAE: 19

1) 9.7 (1.5)

2) 10.7 (0.9)

1) 16

2) 12

1) 94.9 (12.5)

2) 107.5 (11.2)

NA

0

1) 10

2) 14

28

11.1 (1.5)

13

116.7 (15.4)

ROI

Lower global MD in ADHD without prenatal alcohol exposure

Ameis et al., 2016

31

10.3 (1.8)

25

103.4 (12.6)

NA

23

18

62

10.8 (2.8)

37

112.5 (17.1)

TBSS

Reduced FA in the genu and splenium of the CC, CST, ILF, arcuate, and IFOF. ASSOC: FA and adaptive functioning

Aoki et al., 2017

55

9.5 (1.5)

41

110 (14)

ADHD-C: 36

ADHD-I: 16

NOS: 3

25

41

50

9.4 (1.5)

38

114 (13)

TBSS

No group differences. ASSOC: AD in the CC and inattentive symptoms

Ashtari et al., 2005

18

8.94 (1.5)

12

101.89 (20.9)

ADHD-C:18

8

6

15

9.13 (1.4)

9

105.07 (10.0)

VBA

Reduced FA in R premotor, anterior limb IC and cerebral peduncle; L MCP, cerebellum, and parieto-occipital areas

Ball et al., 2019

70

[9.4-11.9]

NA

NA

NA

NA

47

90

[9.4-11.9]

NA

NA

TBSS + multimodal

ASSOC: FA in the fornix, SLF and genu of the CC with hyperactivity

Basay et al., 2016

71

10.88 (1.36)

59

109.42 (18.60)

NA

11

1

24

10.80 (2.02)

18

111.45 (17.84)

TBSS

Reduced FA in the L CING and R retrolenticular IC

Beare et al., 2017

21

13.28 (1.86)

21

96.95 (10.15)

ADHD-C: 21

NA

15

21

14.79 (2.12)

21

111.76 (9.66)

TG + network

Increased connectivity in subnetwork including bilat frontal regions, CING, and putamen, and extending to L fronto-temporo-parieto-occipital regions, thalamus and pallidum. ASSOC: FA cluster strength and symptom severity

Bechtel et al., 2009

1) epilepsy+ ADHD: 8

2) ADHD: 14

1) 11.63 (1.69)

2) 10.43 (1.34)

1) 8 2) 1 4

NA

ADHD-I: 1) 4

2) 5

8

0

12

10.92 (1.64)

12

NA

ROI

Reduced FA in the R MCP

Bessette et al., 2019

67

15.41 (1.78)

55

105.28 (12.06)

ADHD-C:67

29

25

68

15.43 (1.73)

50

108.05 (9.25)

TBSS

ASSOC: FA in the genu of the CC/forceps minor, bilat ACR, bilat post limb IC (CST) with delay aversion

Bos et al., 2017

35

11.2 (2.6)

26

105.5 (15.9)

NA

4

8

36

12.1 (2.2)

29

109.6 (16.4)

TBSS + network

No group differences

Bouziane et al., 2018 (children)

49

11.34 (0.87)

49

104.62 (18.08)

ADHD-C: 21 ADHD-I: 27 ADHD-HI: 1

3

49

11

11.36 (0.84)

11

121.6 (10.9)

TBSS + ROI

No group differences

Bu et al., 2020

38

8.79 (2.11)

29

120.63 (16.34)

NA

0

38

34

9.29 (1.67)

21

122.18 (13.58)

TG

Reduced FA and increased MD in the cerebral peduncle; increased FA in the R CST. ASSOC: FA in the CST and RD in the R peduncle with attention

Cao et al., 2010

28

13.3 (1.5)

28

102.8 (12.9)

ADHD-C: 12

ADHD-I: 16

9

23

27

13.2 (0.9)

27

115.1 (12.7)

ROI

Reduced FA in the isthmus of the CC

Cao et al., 2013

30

10.3 (1.9)

30

107.1 (14.4)

ADHD-C: 15

ADHD-I: 15

11

30

30

10.3 (1.6)

30

121.7 (14)

TG + network

Decreased global efficiency and increased shortest path length in the L fronto-parieto-occipital cortices. ASSOC: decreased structural connectivity in the prefrontal circuitry and increased connectivity in the orbitofrontal-striatal circuitry with inattention and HI symptoms respectively.

Çelik et al., 2020

13

16.0 (1.2)

13

NA

ADHD-C: 13

NA

NA

13

16.5 (1.3)

13

NA

TG + network

Increased structural connectivity in ADHD + cannabis use in a network including L hippocampus, amygdala, MTG, cerebellum and R thalamus. Other edges linked the L amygdala with insula and IFG, and another the cerebellar lobules.

Cha et al., 2015

30

9.4 (2.0)

24

99.1 (15.9)

ADHD-C: 24 ADHD-I: 5 ADHD-HI:1

16

30

31

10.5 (2.1)

21

109.1 (15.7)

TG

Reduced fronto-accumbal connectivity. ASSOC: fronto-accumbal WM and aggression

Chen et al., 2015

33

9.7 (2.2)

32

104.2 (5.2)

ADHD-C: 33

0

33

35

10.5 (1.8)

33

107.1 (6.4)

VBA

Increased FA in the L posterior CING . ASSOC: FA in the CING with behavioral measures and executive functions

Chiang et al., 2015

50

11.26 (2.93)

38

110.28 (11.52)

ADHD-C: 26 ADHD-I: 24

22

NA

50

11.22 (2.79)

38

111.78 (11.02)

TG

Reduced GFA in the L frontostriatal tracts, bilat SLF and R CING. ASSOC: R SLF GFA and inattentive symptoms

Chiang et al., 2016

45

11.36 (2.86)

33

109.98 (11.6)

ADHD-C: 22 ADHD-I: 22 ADHD-HI: 1

0

35

45

11.29 (2.71)

33

111.42 (11.21)

TG

Reduced GFA in the L FS tract, SLF, arcuate and R CING. ASSOC: FA in the FS, SLF and arcuate with executive functions

Chiang et al., 2020

50

12.13 (2.33)

42

103.70 (13.22)

NA

0

50

50

12.00 (2.39)

42

109.35 (11.42)

TG

Increased AD in the perpendicular fasciculus, SLF I, CST, and CC. ASSOC: AD in the SLF I, CST and CC and symptom severity, sustained attention and working memory

Choi et al., 2008

1) ADHD: 15

2) ADHD + tic/Tourette: 24

1) 9.6 (1.8). 2) 10.4 (1.1)

1) 15 2) 24

1) 106.5 (11) 2) 102.7 (10.9)

1) ADHD-C: 15 2) ADHD-C: 24

1) 5 2) 24

1) 0 2) 1

9

9.7 (1.7)

9

121.1 (8.8)

VBA

Decreased FA in the L MCP and R frontal lobe, increased FA in the R middle occipital WM

Chuang et al., 2013

12

14.8 (1.4)

12

99.4 (11.7)

ADHD-C: 8 ADHD-I: 4

7

0

14

15.7 (NA)

14

102.4 (9.3)

TBSS

Lower FA in the MCP, CST, L ILF, IC, L OR, CC (splenium), L ACR, PCR. ASSOC: MCP FA with global cognitive performance; IC FA with executive functions; and PCR FA with attention

Cooper et al., 2014

17

15.6 (1.3)

17

87.6 (9.8)

ADHD-C: 17

NA

1

17

16.9 (1.2)

17

106.9 (7.6)

TBSS

No group differences. ASSOC: FA and RD in the R posterior limb of the IC/CST, R cerebral peduncle and midbrain with autistic traits

Cooper et al., 2015

17

15.6 (1.3)

17

87.6 (9.8)

ADHD-C: 17

NA

1

17

16.9 (1.2)

17

106.9 (7.6)

TG

No group differences. ASSOC: FA and RD in the L subgenual CING with symptom severity, in the R CST with autistic traits

Damatac et al., 2020

258

17.4 (3.6)

182

95.1 (16)

NA

90

56

322

17.2 (3.7)

152

104.3 (14.9)

TG

No group differences. ASSOC: FA in the R CING and HI symptom severity

Davenport et al., 2010

14

15.0 (2.34)

12

113.1 (15.7)

ADHD-C: 13

ADHD-I: 1

NA

0

26

14.8 (2.41)

16

114.2 (10.4)

VBA

Increased FA in L inferior and R superior frontal regions. Reduced FA in the L fornix

de Luis-Garcia et al., 2015

1)medication naïve: 16

2) treated: 24

1) 7.62 (1.36)

2) 8.50 (1.1)

1) 16 2) 24

1) 100.3 (18.2)

2) 103.3 (13.3)

NA

0

16

26

8.23 (1.53)

26

120.3 (14.5)

TBSS + TG

No case-control differences. Medication-naïve vs treated subjects and controls: reduced MD in the ILF, UNC and CC. ASSOC: MD in CST and attention performance

De Zeeuw et al., 2012a

30

9.6 (2.3)

27

104 (17)

ADHD-C:19 ADHD-I: 6 ADHD-HI: 5

11

NA

34

10.2 (2.3)

30

111 (16)

TG

Reduced frontostriatal FA

de Zeeuw et al., 2012b

30

9.6 (2.3)

27

104 (17)

ADHD-C:19 ADHD-I: 6 ADHD-HI: 5

11

NA

34

10.2 (2.3)

30

111 (16)

VBA

No group differences

Douglas et al., 2018

1) whole ADHD sample: 56

2) medication naïve: 29

1) 12.6 (3.2)

2) 12.6 (3.8)

1) 39

2) 21

1) 106.2 (13.1)

2) 106.1 (13.9)

NA

1) 27

2) 0

29

17

13.2 (2)

6

110.4 (13.1)

TG

Differences in diffusivity asimmetry indices in the CING, ILF, SLF and CST

Ercan et al., 2016

1) ADHD-C: 24

2) ADHD-I: 24

3) ADHD-RI: 24

1) 10.5 (1.7)

2) 11.1 (2.0)

3) 10.7 (2.2)

1) 24

2) 18

3) 18

1) 112.5 (20.2)

2) 106.8 (16.6)

3) 108.0 (19.1)

1) ADHD-C: 24

2) ADHD-I (I): 24

3) ADHD-I (RI): 24

1) 8

2) 3

1) 24

2) 24

3) 24

24

10.8 (1.3)

18

111.4 (17.8)

TBSS

No case-control differences. ADHD-C vs ADHD-I: increased RD (bilat) and AD (mostly L) including splenium and body of the CC, IC, superior, anterior and posterior CR, PTR, SLF. ADHD-I vs ADHD-RI: increased FA in the bilat PCR, R superior CR, L CING

Fall et al., 2015

11

9.8 (1.7)

10

VIQ: 112.5 (14.4) PIQ: 103.1 (14.4)

ADHD-C: 11

0

11

11

10.8 (1.7)

8

VIQ: 122.4 (11.7) PIQ: 111.9 (8.8)

ROI

No group differences. ASSOC: MD in the bilat caudate, putamen and thalamus with RT and RTV

Fayed et al., 2007

22

9 (2.91)

18

NA

NA

0

22

8

7.5 (3)

4

NA

ROI

No group differences

Francx et al., 2015

1) Remitters: 42

2) Persisters: 59

1)

T1: 11.9 (2.4)

T2: 17.9 (2.5)

2)

T1: 11.9 (2.8)

T2: 17.8 (2.7)

1) 36

2) 45

1)

T1: 94.5 (12.8)

T2: 96.3 (13.2)

2)

T1: 95.9 (13.9)

T2: 94.1 (15.1)

1) 42

2) 59

1) 13

2) 30

NA

40

T1: 12.9 (2.3)

T2: 17.8 (2.1)

10

T1: 106.4 (13.4)

T2: 106.7 (13.5)

TBSS + TG

ASSOC: lower FA and higher MD in the left CST and SLF, and higher MD in CC and CING, with age-related improvement of HI symptoms

Francx et al., 2016

129

17.8 (3.2)

90

96.9 (15.6)

ADHD-C: 129

41

NA

204

17.3 (3.5)

84

103.0 (13.1)

TBSS

Increased FA in the forceps major. Reduced FA in the IC, CC and PostCG. Increased MD in the PostCG and reduced MD in the thalamus. Increased MA in the bilat superior CR

Fuelscher et al., 2021

76

[9.4-11.5]

56

NA

NA

NA

59

68

[9.6-11.9]

38

NA

TG + FBA

Reduced FD in the bilat CST, frontopontine tract, and L IFOF. ASSOC: FD in the left frontopontine tract and symptom severity

Gau et al., 2015

32

11.4 (2.3)

29

109 (12.2)

ADHD-C: 19 ADHD-I: 13

NA

15

32

NA

NA

112.4 (10.0)

TG

Reduced GFA in four fronto-striatal tracts:caudate–dorsolateral, caudate–medial prefrontal, caudate–orbitofrontal and caudate–ventrolateral tracts. ASSOC: FA and school dysfunction, mediated by executive functions and ADHD symptom severity

Graziano et al., 2022

102

NA (young children)

NA

NA

NA

70

NA

96

NA

NA

NA

TG

Reduced FA in the bilat UNC, IFOF and CST and L ILF. ASSOC: FA in the bilat UNC and L IFOF and callous-unemotional behaviors

Griffiths et al., 2021

37

13.31 (2.53)

NA

NA

ADHD-C:20 ADHD-I:17

NA

NA

26

13.24 (2.87)

NA

NA

TG + network

Reduced local efficiency in the L pallidum, putamen, MTG, PostCG and transverse temproal area; bilat thalamus, and R caudate, pars opercularis and amygdala. ASSOC: local effeciency in the R thalamus, isthmus, CING and pars triangularis, FG, SMG, MFG and in the L SFG and bilat PreCG with treatment-related symptom improvement

Hamilton et al., 2008

17

11.95 (2.32)

17

92.25 (14.55)

ADHD-C:1 ADHD-I: 5 ADHD-HI: 9

10

NA

16

11.72 (2.48)

16

103.35 (10.09)

ROI

Reduced FA in the CST and SLF

Helpern et al., 2011

12

14.4 (1.6)

9

105 (18)

ADHD-C:7 ADHD-I: 5

2

4

13

14.8 (1.7)

7

110 (16)

ROI

No group differences in WM microstructural complexity but lack of age-related changes observed in controls

Hong et al., 2014

1) whole ADHD sample: 71

2) ADHD-C: 39

3) ADHD-I: 26

1) 9.39 (2.59)

2) 9.30 (2.47)

3) 9.78 (2.81)

1) 15

2) 6

2) 6

1) 106.06 (12.47)

2) 105.38 (12.71)

3) 108.31 (11.87)

ADHD-C: 39 ADHD-I: 26

ADHD-HI:1

NOS: 5

16

61

26

10.04 (2.47)

13

117.27 (10.39)

TG + network

Reduced connectivity in a network spanning frontal, striatal, and cerebellar regions. ADHD-C vs ADHD-I: decreased connecitivity in network including SFG, CING, and SMA. ASSOC: FA and omissions, commissions and RTV

Hyde et al., 2021a

50

10.38 (0.43)

35

96.28 (13.34)

NA

26

50

56

10.49 (0.45)

31

102.73 (13.36)

FBA

Reduced FD, FC and FDC in the R CST and reduced FDC in the L CST

Hyde et al., 2021b

55

9.6 (0.42)

39

96.18 (13.16)

NA

32

55

61

9.58. (0.45)

35

103.41 (13.25)

TG

ASSOC: AFD in the R SLF I, and volume of R SLF I, II and III with fine motor control

Jacobson et al., 2015

60

9.9 (1.3)

30

108.6 (12.3)

ADHD-C: 41 ADHD-I: 17 ADHD-HI: 2

19

NA

60

10.2 (1.1)

30

111.9 (10.0)

ROI

ADHD boys: reduced FA in bilat M1; ADHD girls: increased FA bilat within medial OFC. ASSOC: FA and commissions and RTV

King et al., 2015

19

12.68 (2.14)

10

107.53 (11.49)

ADHD-C: 10

ADHD-I: 9

3

3

24

14.42 (2.76)

12

113.59 (8.40)

TBSS + ROI

Reduced FA in the bilat SLF, forceps major, L CING, and bilat CC. Females vs males: increased FA in the CST, ILF and SLF

Kobel et al., 2010

14

10.43 (1.34)

14

NA

NA

7

0

12

10.92 (1.62)

12

NA

VBA

Reduced FA in the L ACR and R MCP; reduced FA in the L temporo-occipital WM

Langevin et al., 2014

1) ADHD only: 23 2) ADHD +DCD:19

1) 11.78 (2.99) 2) 11.39 (2.89)

1) 20 2) 19

1) 107.67 (13.07); 2) 102.35 (14.06)

NA

2) 19

NA

26

11.58 (3.18)

14

114.12 (13.07)

TG

Reduced FA in the anterior/superior frontal CC. ASSOC: FA in the CC with attention/executive functions. FA in the bilat SLF and motor control in those with comorbid DCD

Lawrence et al., 2013

56

12.6 (3.2)

39

105.3 (13.1)

NA

40

29

17

13.2 (2.0)

6

110.4 (13.3)

TG

Increased MD and AD in the ATR, forceps minor and SLF

Lee et al., 2009

11

10.45

7

NA

NA

NA

11

9

10.56

6

NA

ROI

Reduced FA in L ILF and IFOF

Lee et al., 2021

1) ADHD-C: 70

2) ADHD-I: 75

1) 10.0 (2.4)

2) 11.5 (2.9)

1) 56

2) 54

1) 75.8 (41.3)

2) 84.6 (36.2)

1) ADHD-C: 70

2) ADHD-I: 75

1) 19

2) 20

NA

56

10.2 (2.6)

20

66.3 (53.8)

TG + network

Reduced structural connectivity and network efficiency in the DMN

Lei et al., 2014

1) ADHD-C: 28 2) ADHD-I: 28

9.3 (1.3)

25

1) 99.6 (11.3) 2) 96.1 (12.1)

1) ADHD-C: 28 2) ADHD-I: 28

0

1) 28 2) 28

28

9.2 (1.4)

25

99.1 (10.3)

VBA

ADHD-C vs controls: decreased AD and RD in the L MFG, SMA and precuneus; reduced FA in the L PHG, and decreased AD in the L precuneus and R CING. Increased RD in the R FG and MTG, and in the L cuneus, lingual gyrus and STG. ADHD-C vs ADHD-I: metric differences in the R thalamus and caudate, L PostCG, and SMA

Li et al., 2010

24

9.62 (2.19)

22

NA

ADHD-C: 18 ADHD-I: 6

8

24

20

10.12 (1.83)

18

NA

VBA

Increased FA in the R frontal WM. ASSOC: FA with executive functions

Lin et al., 2014

28

11.54 (2.30)

25

107.86 (14.75)

ADHD-C: 17 ADHD-I: 11

0

11

28

11.57 (2.75)

25

107.71 (12)

TG

Reduced GFA in four bilateral frontostriatal tracts. ASSOC: GFA in the CING and frontostriatal tracts with RTV

Lin et al., 2020

14

7.9 (2.1)

0

120.36 (17.21)

ADHD-C: 6 ADHD-I: 7 ADHD-HI: 1

0

14

10

8.9 (0.6)

0

121.60 (18.17)

TG

ADHD girls: reduced FA and increased RD in the callosal forceps major. ASSOC: FA with HI symptoms and impulsivity, RD with impulsivity

Lin et al., 2022

1) whole ADHD sample: 76

2) males: 53

3) females: 23

1) 8.80 (2.25)

2) 9.04 (2.22)

3) 8.26 (2.26)

53

1) 119.78 (15.10)

2) 119.98 (14.83)

3) 119.30 (16.02)

NA

0

1) 76

2) 53

3) 23

1) 37

2) 20

3) 17

1) 9.51 (1.68)

2) 9.20 (1.83)

3) 9.88 (1.45)

20

1) 121.14 (13.37)

2) 121.30 (120.05)

3) 120.94 (15.15)

TG

Reduced FA in the occipital and superior parietal callosal tracts; increased MD in the posterior, superior parietal and anterior frontal tracts. ADHD girls: decreased FA and volume of the occipital tract and increased MD in the posterior and superior parietal tracts. ADHD boys: decreased volume of the frontal tract.

Malisza et al., 2012

20

11.99 (1.32)

18

96.55 (16.87)

NA

5

5

21

12.6 (1.29)

16

107.81 (13.08)

VBA

No group differences

Mazzetti et al., 2022

22

10.7 (1)

100

NA

NA

NA

0

26

10.7 (1.3)

100

NA

TG

ASSOC: FA in the ATR and symptom severity. Dorso-ventral gradient in SLF FA and methylphenidate-induced behavioral improvement

Nagel et al., 2011

20

8.05 (0.69)

13

106.5 (12.8)

ADHD-C: 11 ADHD-I: 8 ADHD-HI: 1

10

17

16

8.31 (0.70)

4

115.4 (12.9)

TBSS

Reduced FA in fronto-parietal, fronto-limbic, cerebellar, CR and temporo-occipital WM. Lower MD in the posterior limb of the IC and fronto-parietal WM, and greater MD in fronto-limbic WM

O’Conaill et al., 2015

19

11.93 (1.33)

17

95.79 (16.97)

NA

5

4

21

12.60 (1.29)

16

107.81 (13.08)

TBSS

No group differences

O’Neil et al., 2019

1) ADHD + PAE: 9

2) ADHD: 11

3) ADHD/?PAE: 4

1) 12.4 (2.1)

2) 11.7 (2.4)

3) 11.8 (1.4)

1) 8

2) 9

3) 1

1) 88.1 (18.0)

2) 92.8 (14.1)

3) 81 (20.3)

1)ADHD-C: 6 ADHD-I: 3

2)ADHD-C: 5 ADHD-I: 5 NOS: 1

3) ADHD-C: 2 NOS: 2

1) 10

2) 11

3) 6

1) 7

2) 10

3) 0

9

13.1(2.2)

2

92.0 (15.4)

TBSS

No group differences

O’Neil et al., 2022

1) ADHD + PAE: 23

2) ADHD - PAE: 19

1) 9.7 (1.6)

2) 10.7 (0.9)

1) 16

2) 12

1) 94.9 (12.8)

2) 107.5 (11.5)

NA

NA

NA

28

11.3 (1.6)

13

116.7 (15.6)

ROI

AD and MD paired with spectroscopic measures of supraventricular WM were discriminative between ADHD (whole group) and controls

Park et al., 2016

1) ADHD+PTE: 29

2) ADHD-PET: 25

1) 9.20 (2.89)

2) 9.12 (1.97)

1) 26

2) 20

1) 104.86 (11.90)

2) 106.42 (13.40)

NA

NA

NA

1) TDC+PTE: 18

2) TDC-PTE: 23

1) 9.78 (3.19)

2) 8.96 (2.01)

1) 12

2) 11

1) 111.11 (15.03)

2) 113.18 (10.99)

TBSS

Widespread areas of increased FA and reduced MD

Pastura et al., 2016

13

8 (1.2)

10

105 (11.5)

ADHD-C: 8 ADHD-I: 4 ADHD-HI: 1

8

1

14

9 (1.3)

10

106 (17.7)

TBSS

Lower FA in the splenium of the CC, R SLF, bilat retrolenticular IC and IFOF, L EC and PTR

Pavuluri et al., 2009

13

13.4 (3.0)

12

94.0 (13.7)

NA

NA

NA

15

13.7 (2.7)

6

113.7 (13.5)

ROI

Reduced FA in the ACR, anterior limb of the IC and the superior IC. Increased ADC in the ACR, anterior and posterior limbs of the IC, superior IC, CING, ILF, and SLF

Peterson et al., 2011

16

11.28 (1.55)

11

108 (14.03)

ADHD-C: 9 ADHD-I: 7

6

NA

16

11.15 (2.14)

11

115 (10.28)

VBA + ROI

VBA: increased FA in the R SFG and PTR, and L CING, lingual gyrus, and PHG. ROI: increased FA in the L sagittal stratum. ASSOC: FA in the L sagittal stratum and symptom severity

Qian et al., 2021

34

9.44 (1.67)

32

104.09 (15.56)

NA

NA

NA

30

9.67 (2.88)

22

107.07 (18.43)

TG + network

Increased betweenness centrality in the L hyppocampus. ASSOC: betweenness centrality in the R hyppocampus and oppositional behavior

Qiu et al., 2011

15

12.65 (1.82)

15

NA

ADHD-I: 15

NA

NA

15

13.21 (1.73)

15

NA

VBA

Decreased FA in the forceps minor, IC, CR, splenium of the CC, and bilat basal ganglia

Ray et al., 2014

20

[8-12]

NA

NA

ADHD-C: 11 ADHD-I: 8 ADHD-HI: 1

NA

NA

20

[8-12]

NA

NA

TG + network

Under-connectedness inside rich-club organization with reduced GFA

Rossi et al., 2015

29

10.14 (1.94)

20

110.60 (14.94)

ADHD-I: 29

NA

NA

29

10.10 (1.63)

19

120.21 (14.96)

TBSS

No group differences. ASSOC: FA in the bilat CST and UNC, R CING and IFOF, forceps minor and major with attention performance

Saad et al., 2021

1) ADHD-C: 19

2) ADHD-I: 18

1) 13.25 (2.53)

2) 13.35 (2.65)

1) 15

2) 14

NA

1) ADHD-C: 19

2) ADHD-I: 18

1) 7

2) 3

1) 8

2) 12

28

13.09 (2.63)

9

NA

TBSS + TG + network

No group differences in TBSS/TG analysis. Difference in nodal degree (R insula)

Saenz et al., 2020

36

10.47 (1.33)

21

105.53 (10.85)

ADHD-C: 36

0

NA

20

118.10 (13.26)

10

109.39 (9.22)

TBSS

No group differences. ASSOC: MD in the SLF and CING with working memory

Shang et al., 2013

25

11.4 (2.1)

22

108.4 (12.7)

ADHD-C: 16 ADHD-I: 8 ADHD-HI: 1

0

7

25

11.4 (2.7)

22

111.1 (10.9)

TG

Reduced GFA in four fronto-striatal tracts. ASSOC: GFA and symptom severity and executive functions

Silk et al., 2009a

15

12.6 (2.4)

15

PIQ 104.9 (11.5)

ADHD-C: 15

0

12

15

12.9 (2.6)

15

PIQ 111.6 (9.2)

ROI

No group differences in tract metrics

Silk et al., 2009b

15

12.6 (2.4)

15

PIQ 104.9 (11.5)

ADHD-C: 15

0

12

15

12.9 (2.6)

15

PIQ 111.6 (9.2)

TBSS

Increased FA in the R CING and SLF, and in the L UNC and ILF.

Silk et al., 2016

21

13.3 (1.8)

21

94.3 (11.3)

ADHD-C: 21

NA

15

22

14.6 (2.2)

22

110.3 (8.5)

TG

L lateralized FA in the putamen-ventrolateral PFC. ASSOC: FA and symptom severity

Stephens et al., 2021

1) ADHD: 62

2) ADHD+ASD: 16

1) 10.3 (0.5)

2) 10.7 (0.5)

1) 45

2) 12

NA

NA

NA

NA

73

10.4 (0.4)

41

NA

TG

Reduced FA in R CING. ASSOC: FA in the L CING and emotional problems in comorbid ADHD+ASD

Sun et al., 2018

83

10.83 (2.30)

71

NA

ADHD-C: 43 ADHD-I: 40

NA

83

87

11.21 (2.51)

72

NA

ROI + machine learning

Features discriminating ADHD vs controls included FA in the L cerebral peduncle; ADHD-C vs ADHD-I included FA in the L EC

Svatkova et al., 2016

1) ADHD-C: 13

2) ADHD-PI: 20

1) 12.78 (2.32)

2) 14.95 (2.37)

1) 10

2) 16

1) 109.5 (7.6)

2) 103.9 (11.2)

1)ADHD-C: 13

2) ADHD-I: 20

0

1) 6

2) 6

23

14.15 (2.84)

16

110.4 (9.2)

TBSS

ADHD-I vs controls: higher FA in the ATR, bilat ILF and L CST. ADHD-C vs controls: higher FA in the bilat CING. ADHD-I vs ADHD-C: higher RD in the forceps minor. ASSOC: FA in the R ILF and CING with executive functions; FA in the R ILF with attentive symptom severity

Tamm et al., 2012

12

15.8 (1.5)

12

106.1 (10.8)

ADHD-C: 12

11

NA

12

15.6 (0.8)

12

111.6 (11.7)

TBSS

Increased FA and AD in ACR, ATR, UNC, IFOF, forceps; higher AD in the genu of the CC.

Tremblay et al., 2020

60

10.6 (2.6)

50

101

ADHD-C: 43 ADHD-I: 13 ADHD-HI: 4

NA

NA

16

10.5 (4.86)

5

111

TG

No significant group differences

Tsai et al., 2021

77

11.77 (2.41)

62

108.4 (10.6)

NA

11

60

105

12.39 (2.82)

85

110.3 (11.6)

TG

ASSOC: GFA in widespread tracts including bilat ILF, stria terminalis, arcuate; L CING, IFOF, UNC, TR, posterior commissure, CC; and R SLF II with emotion dysregulation, symptom severity and IQ

Unsel-Bolat et al., 2020

1) SCT+ADHD-IA: 24

2) ADHD-IA: 57

1) 9.25 (1.3)

2) 10.8 (1.9)

1) 17

2) 36

NA

1) ADHD-I: 24

2) ADHD-I: 57

0

1) 24

2) 57

24

10.8 (1.3)

18

NA

TBSS

ADHD+ SCT symptoms: higher FA in the bilat anterior and posterior limbs of the IC, cerebral peduncle and fornix

Wang et al., 2008

16

11.4 (1.2)

12

NA

ADHD-C: 4 ADHD-I: 12

NA

16

16

10.9 (1.4)

11

NA

TG

Reduced FA in R pericallosal WM and bilat CING. ASSOC: FA in R CING and bilat MCP and reaction time

Wang et al., 2020

1) Dataset 1: 25

2) Dataset 2: 11

1) 11.05 (1.68).

2) 11.71 (2.13)

1) 24

2) 11

1) 108.1 (16.7)

2) 114.36 (13.86)

1) ADHD-C: 25

2) ADHD-C: 11

NA

NA

1) 45

2) 26

1) 11 (1.40)

2) 11.98 (1.77)

1) 35

2) 26

1) 121.3 (13.6) 2)

119.04 (12.80)

TG + network

Increased trace-map distance in regions near the L parietooccipital junction

Wu et al., 2014

25

11.36 (2.14)

22

108.40 (12.69)

ADHD-C: 16 ADHD-I: 8 ADHD-HI: 1

19

7

25

11.40 (2.69)

22

111.12 (10.91)

TG

Reduced GFA in four fronto-striatal tracts. ASSOC: GFA in the L orbito-frontal caudate tract and inattentive symptom severity

Wu et al., 2017

83

11 (1.99)

73

107.1 (14.41)

NA

32

69

122

10.6 (1.81)

60

118.7 (13.2)

TBSS

Decreased FA and increased RD mainly in CC, L SLF, L anterior and superior CR. ASSOC: reduced FA and inhibition; increased FA and HI symptom severity

Wu et al., 2019

80

10.95 (1.95)

71

106.96 (14.37)

NA

32

67

119

10.62 (1.82)

58

118.64 (13.16)

TBSS + multimodal

Reduced FA, increased RD and MD in the ATR, CING, body of the CC and CST. ASSOC: FA in bilat SLF and IFOF, and RD and MD in CST and ATR with symptom severity

Wu et al., 2020a

30

10.64 (1.69)

23

95 (13.81)

NA

NA

8

28

10.61 (1.73)

18

112 (17.51)

TG

Lower axonal/cellular packing density and volume primarily in the R SLF-II, thalamus to PreCG and SFG, caudate to OFC and PreCG, thalamus to L paracentral gyrus and MFG, and bilat CING

Wu et al., 2020b

83

11 (1.99)

73

107.1 (14.41)

NA

NA

NA

122

10.6 (1.81)

60

118.7 (13.2)

TBSS

FA lateralization index increased in PTR. ASSOC: lateralization index in EC and inattentive symptoms

Wu et al., 2022

1) ADHD-C: 41

2) ADHD-I: 76

1) 8.44 (1.21)

2) 8.92 (1.47)

1) 36

2) 59

NA

1) ADHD-C: 41

2) ADHD-I: 76

0

100

83

9.39 (1.37)

44

NA

TBSS

ADHD-C vs controls: increased volume body of the CC. ADHD-I vs controls: increased AD in the CC, bilat CR, EC, SLF, and L IC, CING, CST, and superior fronto-occipital fasciculus. ADHD-C vs ADHD-I: reduced AD in the CC, bilat EC, IC, CR; L TR, tapetum and superior fronto-occipital fasciculus; and R SLF

Xia et al., 2012

19

10.9 (2.3)

14

102.8 (17)

ADHD-C: 19

NA

11

19

12.2 (2.3)

10

110.5 (12.6)

TG

Decreased FA and volume in the tracts between thalamus and striatum, hippocampus, and PFC

Yoncheva et al., 2016 (children)

82

10.63 (2.8)

64

105.52 (14.9)

ADHD-C: 50 ADHD-I: 26 ADHD-HI: 4

27

59

80

11.04 (2.6)

55

108.98 (14.3)

TBSS

Reduced global MA. ASSOC: MA and symptom severity

Yoo et al., 2020

1) Training sample: 47

2) Independent sample: 18

1) 10.06 (2.24)

2) 9.44 (2.41)

1) 37

2) 12

1) 110.53 (14.38) 2) 114.17 (13.08)

1) ADHD-C: 14 ADHD-I: 22 ADHD-HI: 3 NOS: 8

2) ADHD-C: 5 ADHD-I: 5 ADHD-HI: 4 NOS: 4

0

NA

1) 47

2) 18

1) 10 (2.60)

2) 10.06 (2.69)

1) 29

2) 10

1) 110.53 (14.38)

2) 114.61 (14.01)

TBSS + machine learning

Overall diffusivity scalars contributed to classification ADHD vs controls

Zhan et al., 2017

32

11.1 (0.3)

25

104.3 (2.4)

ADHD-C: 32

0

23

32

11.9 (0.4)

19

108.1 (2.3)

ROI + network

Increased RD in subgenual CING and premotor cortex. ASSOC: RD and symptom severity

Zhou et al., 2021

116

[9-10]

71

NA

NA

0

NA

116

[9-10]

71

NA

ROI + machine learning

Discriminative features included: FA in the R pars orbitalis and L PostCG; MD in the R CING and L amygdala; AD in the R CING and thalamus