Table 2.

Descriptive Statistics

Measure	Cronbach’s α	Possible Range of Scores	Mean Full Sample (SD)	Mean Males (SD)	Mean Females (SD)	Skew
A-TACa	0.92	0−19	2.10 (3.21)	2.54 (3.54)	1.62 (2.73)	2.34
Conners ADHDb	0.91	0−54	10.84 (9.00)	12.67 (9.71)	9.04 (7.85)	1.37
A-TAC Hyp/Impc	0.89	0−10	0.99 (1.69)	1.17 (1.85)	0.81 (1.48)	2.53
A-TAC Inattend	0.90	0−9	1.03 (1.73)	1.28 (1.91)	0.78 (1.49)	2.23
Conners Hyp/Impe	0.89	0−27	5.57 (4.93)	6.39 (5.28)	4.78 (4.41)	1.33
Conners Inattenf	0.91	0−27	5.27 (5.04)	6.29 (5.45)	4.26 (4.37)	1.41

Note: ADHD = attention-deficit/hyperactivity disorder; A-TAC = Autism-Tics and Other Comorbidities Inventory; Conners ADHD = ADHD subscale of the Conners’ Parent Rating Scale; Hyp = hyperactivity; Imp = impulsivity; Inatten = inattention.

^aMean A-TAC scores were significantly higher for males than females in the full sample (t_6539.22 = 11.90, p < .001, d = 0.29).

^bMean Conners ADHD scores were significantly higher for males than females in the full sample (t_3843.64 = 13.08, p < .001, d = 0.42).

^cMean A-TAC Hyperactivity/Impulsivity scores were significantly higher for males than females in the full sample (t_6431.70 = 8.95, p < .001, d = 0.22).

^dMean A-TAC Inattention scores were significantly higher for males than females in the full sample (t_6369.05 = 12.08, p < .001, d = 0.30).

^eMean Conners ADHD Hyperactivity/Impulsivity scores were significantly higher for males than females in the full sample (t_3890.60 = 10.50, d = 0.34).

^fMean Connors ADHD Inattention scores were significantly higher for males than females in the full sample, t(_3829.86) = 13.02, p < .001.