The SSS is a participant-rated measure of sleepiness, frequently used for both research and clinical purposes. The SSS evaluates sleepiness at specific moments in time. Respondents rate their current degree of sleepiness and alertness on a scale of 1 to 7, where the lowest score of '1' indicates the respondent is 'feeling active, vital, alert, or wide awake' and the highest score of '7' indicates the respondent is 'no longer fighting sleep, sleep onset soon; having dream-like thoughts'.

Response is defined as >=50 percent (%) reduction from baseline in HAM-D total score. The HAM-D is a 17-item scale used to rate the severity of depression in participants who are already diagnosed as depressed. The total scores of HAM-D range from 0-52. Higher score indicates more depression.

Remission is defined as <=7.0 HAM-D total score. The HAM-D is a 17-item scale used to rate the severity of depression in participants who are already diagnosed as depressed. The total scores of HAM-D range from 0-52. Higher score indicates more depression.

The CGI-I item employs a 7-point Likert scale to measure the overall improvement in the participant's condition posttreatment. The clinician will rate the participant's total improvement, whether or not it is due entirely to investigational product treatment. Response choices include: 0 = not assessed, 1 = very much improved, 2 = much improved, 3 = minimally improved, 4 = no change, 5 = minimally worse, 6 = much worse, and 7 = very much worse. CGI-I response will be defined as having a CGI-I score of "very much improved" or "much improved."

The CGI-S item uses a 7- point Likert scale to rate the severity of the patient's illness at the time of assessment, relative to the clinician's past experience with patients who have the same diagnosis. Considering total clinical experience, a patient is assessed on severity of mental illness at the time of rating. Choices include: 1 = normal, not at all ill; 2 = borderline mentally ill; 3 = mildly ill; 4 = moderately ill; 5 = markedly ill; 6 = severely ill; and 7 = extremely ill.

The HAM-D Bech 6 subscale score is calculated as the sum of the following six items: Item # 1 (depressed mood), Item # 2 (feelings of guilt), Item # 7 (work and activities), Item # 8 (retardation), Item # 10 (anxiety psychic), and Item # 13 (general somatic symptoms). Each item is scored in a range of 0 to 2 or 0 to 4, with higher scores indicating a greater degree of depression. The scores will be transformed to a 100-point scale with a higher score indicating a greater degree of depression. A negative change from baseline indicates less depression. A positive change from baseline indicates more depression.

The HAM-D comprises individual ratings of the following symptoms scored in a range of 0 to 2: insomnia (early, middle, late), somatic symptoms (gastrointestinal and general), genital symptoms, loss of weight, and insight. The following symptoms are scored in a range of 0 to 4: agitation, depressed mood, feelings of guilt, suicide, work and activities, retardation, anxiety (psychic and somatic), and hypochondriasis. Higher scores indicate a greater degree of depression. A negative change from baseline indicates less depression. A positive change from baseline indicates more depression.

The 14-item HAM-A will be used to rate the severity of symptoms of anxiety. Each of the 14 items is defined by a series of symptoms and measures both psychic anxiety (mental agitation and psychological distress) and somatic anxiety (physical complaints related to anxiety). Scoring for the HAM-A is calculated by assigning scores of 0 (not present) to 4 (very severe), with a total score range of 0 to 56, where less than (<) 17 indicates mild severity, 18 to 24 mild to moderate severity, and 25 to 30 moderate to severe severity. The HAM-A total score will be calculated as the sum of the 14 individual item scores.