Table 1. Socio-demographic characteristics and measures of ADHD, anxiety and depression symptom and cognitive performance in the sample.

		MA (n = 1907)		OA (n = 1536)
		Mean (SD)/freq	Std. Res	Mean (SD)/freq	Std. Res	t/χ2	df	p
Gender						7.365	1	0.007
	Males	907 (47.6%)	−1.3	802 (52.2%)	1.4
	Females	1000 (52.4%)	1.3	734 (47.8%)	1.4
Age (years)		50.7 (1.5)		70.6 (1.5)		−386.499	3441	<0.001
Education (years)		14.9 (2.2)		14.1 (2.6)		9.690	3441	<0.001
ASRS-6 score		8.15 (3.40)		6.80 (3.25)		11.824	3441	<0.001
ASRS strata						89.324	3	<0.001
	I	1291 (67.7%)	−3.1	1251 (81.4%)	3.5
	II	499 (26.2%)	4.1	251 (16.3%)	−4.6
	III	99 (5.2%)	3.3	29 (1.9%)	−3.7
	IV	18 (0.9)%	1.5	5 (0.3%)	−1.6
ASRS score categories						31.203	1	<0.001
	0–13	1790 (93.9%)	−0.8	1502 (97.8%)	0.9
	14–24	117 (6.1%)	3.6	34 (2.2%)	−4.1
Depression symptoms present						24.620	1	<0.001
	Yes	258 (13.5%)	3.1	126 (8.2%)	−3.5
	No	1644 (86.2%)	−1.1	1410 (91.8%)	1.2
Anxiety symptoms present						19.227	1	<0.001
	Yes	106 (5.6%)	2.9	39 (2.5%)	−3.2
	No	1801 (94.4%)	−0.6	1497 (97.5%)	0.7
Spot-the-Word Testa		51.77 (4.98)		53.27 (4.92)		−8.800	3441	<0.001
Trail Making Test-A (seconds)b		25.78 (7.35)		35.55 (12.34)		−28.813	3441	<0.001
Trail Making Test-B (seconds)b		57.40 (20.13)		82.57 (31.83)		−28.230	3441	<0.001
Simple Reaction Time (seconds)b		0.24 (0.05)		0.28 (0.07)		−21.618	3441	<0.001
Choice Reaction Time (seconds)b		0.30 (0.04)		0.34 (0.05)		−28.206	3441	<0.001
Immediate Recalla		8.18 (2.17)		6.70 (2.21)		19.637	3441	<0.001
Delayed Recalla		7.38 (2.37)		5.98 (2.32)		17.401	3441	<0.001
Symbol-Digit Modalities Testa		59.73 (8.54)		48.58 (8.79)		37.595	3441	<0.001
Digit Span Backwardsa		5.75 (2.29)		5.17 (2.17)		7.578	3441	<0.001

MA: middle-age cohort; OA: older-age cohort; ASRS: adult ADHD Self-Report Scale; freq: frequency; Std. Res: standardised residuals.

^anumber of correct responses;

^btime taken to complete.