Long-term neurocognitive effects of methylphenidate in patients with attention deficit hyperactivity disorder, even at drug-free status

Table 2 TOVA performance for patients with ADHD at baseline, and at months 6 and month 12 after methylphenidate treatment

	Month 0 (N = 103)	Month 6 (N = 75)	Month 12 (N = 75)	Statistic^a	Post-hoc tests
Omission errors	−1.09 (1.55)	−1.00 (1.47)	−1.17 (1.61)	0.90 (0.408)	NS
Commission errors	−0.22 (1.49)	0.01 (1.22)	0.16 (1.05)	3.66 (0.029)*	Month 12 > Month 0 **
Response time	−0.83 (1.40)	−0.75 (1.24)	−0.79 (1.23)	0.43 (0.654)	NS
Response time variability	−1.06 (1.47)	−0.91 (1.31)	−0.99 (1.36)	1.17 (0.315)	NS
Response sensitivity (d’)	−0.85 (0.88)	−0.65 (0.92)	−0.67 (0.93)	3.71 (0.026)*	Month 6 > Month 0 **
ADHD score	−2.22 (3.29)	−2.00 (3.08)	−2.09 (3.23)	0.95 (0.390)	NS

Note: TOVA results are reported as standard deviations from the norm, and expressed as mean (SD); month 0 data is pretreatment data; ^a statistical values are expressed as F (p-value) using linear mixed model analysis; NS = non-significant; *p<0.05, **p<0.01.

ISSN: 1471-244X