A central scoring facility was used to derive the PSG sleep parameters Latency to Persistent Sleep (LPS) from the epochs and stages collected via the PSG recordings. Each epoch is 30 seconds. The PSG parameters provided an objective assessment of the subject's sleep on a given night. Change from BL at Week 12 in LPS was derived from Week 12 LPS subtracted by BL LPS. Latency to persistent sleep (LPS; minutes): time from lights out to the first of 20 consecutive epochs (10 minutes) of non-wake, as determined by PSG recordings.

Intent to treat (ITT) population with both baseline and week 12 LPS. ITT refers to only the subjects who were randomized AND had taken at least one dose of study drug during the doubleblind treatment period.

A central scoring facility was used to derive the PSG sleep parameters Wake Time After Sleep Onset (WASO) from the epochs and stages collected via the PSG recordings. Each epoch is 30 seconds. The PSG parameters provided an objective assessment of the subject's sleep on a given night. Change from BL at Week 12 in WASO was derived from Week 12 WASO subtracted by BL WASO. Wake time after sleep onset (WASO; minutes): The number of wake epochs after the onset of persistent sleep to the end of the recording, divided by 2.

Intent to treat population with both baseline and Week 12 WASO

The CGI-I Parent/Caregiver was completed by the investigator based on interviews and interactions with the subject's parent or caregiver and represented their assessment of severity and improvement in the subject's symptoms since the start of the study. A 7 point scale was used for improvement with numeric values assigned to each of the responses: very much improved (1), much improved (2), minimally improved (3), no change (4), minimally worse (5), much worse (6), and very much worse (7).

Intent to treat population with Week 12 CGI Improvement from Parent/Caregiver

The CGI - I Child was completed by the investigator based on interviews and interactions with the subject and represented the subject's assessment of improvement in his/her symptoms since the start of the study. A 7 point scale was used for improvement with numeric values assigned to each of the responses: very much improved (1), much improved (2), minimally improved (3), no change (4), minimally worse (5), much worse (6), and very much worse (7).

Intent to treat population with Week 12 CGI Improvement from Child

The Conners' 3 -Parent Short Form was completed by the parent and provided an assessment of Attention-Deficit/ Hyperactivity Disorder (ADHD) and the most common comorbid problems and disorders in children and adolescents. It is a multi-informant assessment of children and adolescents between 6 and 18 years of age that took into account home, social and school settings. The short version of the Conners' 3 -Parent Short Form was a subset of items from the full-length form, and included the Conners' 3 Content Scales of Inattention, Hyperactivity/Impulsivity, Learning Problems, Executive Functioning, Aggression, and Peer/Family Relations. The scale scores were presented as standardized age and gender based t scores. Inattention score was used for this endpoint. The lowest scale score is 40 (best) and the highest is 90 (worse)].

Intent to treat population with both baseline and Week 12 Conners' ADHD Inattention rating scale

A Sponsor produced sleep questionnaire asked the subject or parent/guardian to report information about the subject's sleep and daytime functioning since the last visit. This questionnaire provided a subjective assessment of SL over a pre-defined time period. SL is subjective time to fall asleep.

Intent to treat population with both baseline and Week 12 Subjective sleep latency

A Sponsor produced sleep questionnaire asked the subject or parent/guardian to report information about the subject's sleep and daytime functioning since the last visit. This questionnaire provided a subjective assessment of WASO over a pre-defined time period. WASO is the aggregate duration of awakenings from the time subjects fall asleep until last awakening. Wake time after sleep onset (WASO; minutes): The number of wake epochs after the onset of persistent sleep to the end of the recording, divided by 2.

Intent to treat population with both baseline and Week 12 subjective WASO

A central scoring facility was used to derive the PSG sleep parameter of Sleep Efficiency (SE) from the epochs and stages collected via the PSG recordings. The PSG parameters provided an objective assessment of the subject's sleep on a given night. Sleep efficiency: (total sleep time)/(total recording time) x 100. For this endpoint, total sleep time was defined as the number of non-wake epochs from the beginning of recording to the end of recording divided by 2. If total recording time was greater than 960 epochs (480 minutes), total sleep time was calculated from the PSG truncated at 480 minutes.

Intent to treat population with both baseline and Week 12 PSG defined sleep efficiency

A central scoring facility was used to derive the PSG sleep parameter of Number of Awakenings after Sleep Onset (NAASO). The PSG parameters provided an objective assessment of the subject's sleep on a given night. Number of awakenings: The number of times, after onset of persistent sleep, that there was a wake entry of at least one-minute duration. Each awakening must have been separated by an epoch of non rapid eye movement (NREM) sleep stage 2, 3/4, or rapid eye movement (REM) sleep.

Intent to treat population with both baseline and Week 12 PSG defined of Awakenings After Sleep Onset

A central scoring facility was used to derive the PSG sleep parameter of Total Sleep Time (TST) from the epochs and stages collected via the PSG recordings. The PSG parameters provided an objective assessment of the subject's sleep on a given night. Total sleep time was defined as the number of non-wake epochs from the beginning of recording to the end of recording divided by 2. If total recording time was greater than 960 epochs (480 minutes), total sleep time was calculated from the PSG truncated at 480 minutes.

Intent to treat population with both baseline and Week 12 PSG defined Total Sleep Time

A Sponsor produced sleep questionnaire asked the subject or parent/guardian to report information about the subject's sleep and daytime functioning since the last visit. This questionnaire provided a subjective assessment of TST over a pre-defined time period. TST is subjective total sleep time.

Intent to treat population with both baseline and Week 12 subjective Total Sleep Time

A central scoring facility was used to derive the actigraphy sleep parameter of Sleep Latency (SL). Actigraphy data were used for additional efficacy evaluation as well as for the evaluation of rebound and withdrawal effects.

The Actigraphy population included subjects in the ITT population for whom actigraphy data had been collected. All efficacy analyses of actigraphy data were performed using this population

A central scoring facility was used to derive the actigraphy sleep parameters Wake Time After Sleep Onset (WASO). Actigraphy data were used for additional efficacy evaluation as well as for the evaluation of rebound and withdrawal effects.

Actigraphy population which included subjects in the ITT population for whom actigraphy data had been collected. All efficacy analyses of actigraphy data were performed using this population

A central scoring facility was used to derive the actigraphy sleep parameter of Total Sleep Time (TST). Actigraphy data were used for additional efficacy evaluation as well as for the evaluation of rebound and withdrawal effects.

The Actigraphy population included subjects in the ITT population for whom actigraphy data had been collected. All efficacy analyses of actigraphy data were performed using this population

The PDSS is a validated measure of excessive sleepiness specifically designed for use in school aged children. The scale allowed for measurement of sleepiness across several relatively sedentary activities and provided a means to unmask sleepiness that may not be recognized during more active situations. It consisted of 8 items that assessed the frequency of a sleep related behavior (eg, how often do you fall asleep or get drowsy during class periods; are you usually alert most of the day; how often do you think you need more sleep) using a 5-point Likert type scale (0 = never, 4 = always). All items were summed to obtain the PDSS total score. PDSS data were used for efficacy evaluation as well as for the evaluation of residual effects.The overall PDSS scores range from a low of 0 where the individual is endorsing each item at the lowest level of sleepiness to a high of 32 where the individual is endorsing each item at the highest level of sleepiness.

Intent to treat population with both baseline and Week 12 in Pediatric Daytime Sleepiness Scale (PDSS) Total Score

These tests are standardized information processing tasks to assess recognition and recoding of sensory information. The subject was given 90 seconds to complete as many substitutions of symbols as possible according to a code provided on top of the sheet. The Coding Copy Subtest A was used for subjects 6-7 years of age and the Coding Copy Subtest B was used for subjects 8-16 years of age, and the DSST was used for subjects 17 years of age. The score is the number of squares filled in correctly. Individuals are measured against their own pre-treatment baseline to determine levels of impairment using the scaled score. Higher scores mean less impairment (or potentially improvement) as the number of correct substitutions generally improves as cognition improves. Scaled scores are used to account for age differences among test takers. Scaled scores range from 1 to 19, and higher scores indicate higher cognitive function.

Intent to treat population with both baseline and Week 12 Coding Copy Subtest / Digit Symbol Substitution Test (DSST) Scaled Score

The SF 10 Health Survey for Children is a 10 item care-giver completed assessment designed to measure children's health-related quality of life. The scale asked questions about the child's physical wellness, feelings, behavior, and activities at school and with family and friends. The SF 10 Physical and Psychosocial summary measures were scored such that higher scores indicated more favorable functioning.

Intent to treat population with both baseline and Week 12 Pediatric Quality-of-Life Scale (Short Form-10)

A Sponsor produced sleep questionnaire asked the subject or parent/guardian to report information about the subject's sleep and daytime functioning since the last visit. This questionnaire provided a subjective assessment of NAASO over a pre-defined time period.

Intent to treat population with both baseline and Week 12 Subjective Number of Awakenings After Sleep Onset (NAASO)

School tardiness/attendance reports were to be collected when subject was actively enrolled in school (fall and spring semesters only; summer school, camps or other school attendance was not recorded.) The School Tardiness Report captured the number of days that the subject was tardy to school, had partial attendance at school or was completely absent from school. Data were collected for the 30-day period prior to Baseline, 6-week period prior to Week 6, 6-week period prior to Week 12.

Intent to treat population

School tardiness/attendance reports were to be collected when subject was actively enrolled in school (fall and spring semesters only; summer school, camps or other school attendance was not recorded.) The School Tardiness Report captured the number of days that the subject was tardy to school, had partial attendance at school or was completely absent from school. Data were collected for the 30-day period prior to Baseline, 6-week period prior to Week 6, 6-week period prior to Week 12.

Intent to treat population