7) 0.2463  Anger 37 (46.3) 168 (34.4) 0.0447  Irritability 48 (60.0) 196 (40.1) 0.0010  Active defiance of reasonable requests 36 (45.0) 197 (40.3) 0.4626  Tendency to blame other people 20 (25.0) 89 (18.2) 0.1677  Challenges with school/work performance 60 (75.0) 363 (74.2) 1.0000  Social problems when interacting 50 (62.5) 272 (55.6) 0.2747  Difficulty making the right choices 23 (28.8) 113 (23.1) 0.3218 GPCR Compound Library manufacturer  Inappropriate behavior 48 (60.0) 215 (44.0) 0.0107  Other 3 (3.8) 19 (3.9) 1.0000  Sleeping troubles 0 (0.0) 4 (0.8) 1.0000  Any

core symptoms 77 (96.3) 476 (97.3) 0.4812  Any behavioral symptoms 78 (97.5) 463 (94.7) 0.4056 Currently on behavioral therapy [n (%)]     0.0004  Yes 48 (60.0) 188 (38.4)    No 32 (40.0) 301 (61.6)   ADHD impairment levela (scale 1–10), mean (SD)  Inattention 7.91 (1.77) 7.79 (1.70) 0.5374  Hyperactivity 7.63 (2.13) 7.13 (2.20) 0.0597  Impulsivity 7.55 (2.26) 6.79 (2.36) 0.0074  Anger 7.00 (2.44) 5.27 (2.54) <0.0001  Irritability 6.85 (2.61) 5.69 (2.42) <0.0001  Defiance 7.06 (2.20) 5.88 (2.45) <0.0001  Blame others 5.68 (2.48) 4.64 (2.43) 0.0004  School/work HDAC inhibitor performance 7.86 (1.93) 7.73 (1.71) 0.5418  Social interactions 7.60 (2.10) 6.77 (2.21) 0.0017  Making right choices 6.41 (2.12) 5.45 (2.16) 0.0002  Inappropriate behavior 7.24 (2.17) 6.28 (2.23) 0.0004  Other symptoms 7.67 (2.08) 8.16 (1.95) 0.6916 Mean ADHD symptoms levela (scale 1–10), mean (SD)  ADHD core symptomsb 7.70 (1.59) 7.23 (1.54) 0.0138  Behavior symptomsc 6.96

(1.57) 5.96 (1.61) <0.0001  Other symptoms 7.67 (2.08) 8.16 (1.95) 0.6916  All symptomsd 7.16 (1.47) 6.32 (1.43) <0.0001 Other baseline characteristics  Number of pre-existing co-morbidities: mean (SD) 3.69 (2.16) 2.39 (1.94) <0.0001  Patient engageda (scale 1–10) mean (SD) 6.00 (2.28) 6.61 (1.95) 0.0114 PCM psychotropic concomitant medication, ADHD Sitaxentan attention-deficit/hyperactivity disorder, SD standard deviation aScale from 1 = lowest/none to 10 = highest bCalculated as the mean impairment for hyperactivity,

inattention, and impulsivity cCalculated as the mean impairment for anger, irritability, active defiance, tendency to blame others, challenges with school/work performance, social problems when interacting with family/teachers and peers/colleagues, or difficulty making right choices dCalculated as the mean impairment for all symptoms After controlling for baseline covariates in the multiple logistic regression model (C-statistic = 0.76), several variables remained significant predictors of PCM use, including the number of pre-existing co-morbidities [odds ratio; OR (95 % confidence interval; CI) = 1.16 (1.01, 1.33), P = 0.03], high impairment due to symptom of anger [OR (95 % CI) = 1.79 (1.29, 2.47) per 1 standard deviation increase, P = 0.0005], and country [France: OR (95 % CI) = 3.37 (1.16, 9.75), P = 0.03; Italy: OR (95 % CI) = 5.11 (1.65, 15.79), P = 0.005; the Netherlands: OR (95 % CI) = 3.74 (1.18, 11.78), P = 0.025; and Spain: OR (95 % CI) = 3.73 (1.18, 11.78), P = 0.02 vs.