The primary purpose of this study is to test the efficacy of Lisdexamfetamine in Adults With Attention Deficit Hyperactivity Disorder (ADHD) and Sluggish Cognitive Tempo (SCT). This is a placebo controlled, cross-over clinical trial of oral Lisdexamfetamine Dimesylate 30-70mg/day in adults with attention-deficit hyper-activity disorder and Sluggish Cognitive Tempo (ACT). Patients will be assigned either LDX/Placebo for 10 weeks with a two week placebo washout period.

Sluggish Cognitive Tempo (SCT) describes individuals who are dreamy, spacey, slow moving, hyper active, have difficulty initiating tasks, and often seem under-motivated and under-aroused. Barkley identified nine cardinal symptoms of SCT: 1) prone to daydreaming instead of concentrating; 2) trouble staying alert/awake in boring situations; 3) being easily confused; 4) being easily bored; 5) feeling spacey/in a fog; 6) frequently feeling lethargic; 7) being under-active/having less energy than others; 8) being slow moving; 9) not processing information quickly/accurately. Individuals were identified as SCT if they had at least 5 of 9 symptoms rated often or very often on the 9-item SCT subscale from the Barkley Adult ADHD Rating Scale-IV: Self-Report (BAARS-IV; hereafter called the Barkley SCT Scale).

This is a 2 Site (NYU and Mount Sinai) Study of LDX in 50 adults with Attention Deficit Disorder (ADHD) and Sluggish Cognitive Tempo (SCT). The study will be a double-blind, 10-week, cross-over treatment trial of LDX (4 weeks; 30 - 70 mg/day) vs. placebo (4 weeks) with an intervening single- blind placebo washout period (2 weeks). During the LDX treatment period, LDX treatment will be initiated at a dose of 30mg/day at Visit 0 and can be titrated up (in the judgment of the investigator) in increments of 20mg, based upon clinical response and tolerability, to 50mg/day at Visit 1 and 70mg/day at Visit 2. Subjects receiving daily doses of 50mg or 70mg of LDX will be allowed to down titrate one dosage step of 20mg during Visits 2-4 if (in the judgment of the investigator) they are having issues in tolerability. The highest effective dose of LDX will then be maintained until Visit 4. Patients will be seen weekly throughout the trial except during placebo washout.

Inclusion Criteria:

1. Male or female between the ages of 18-60 of all races and ethnicity.
2. Meets DSM-IV-TR criteria for a primary diagnosis of inattentive or combined type ADHD as diagnosed via the Adult ADHD Clinician Diagnostic Scale
3. For the Sluggish Cognitive Tempo+ group Must Score ≥ 5 items on the Barkley Sluggish Cognitive Tempo Scale; Must be rated 3 ("often") or ("very often") and total Sluggish Cognitive Tempo symptom score ≥ 26; must have a T-score ≥ 65 on the Metacognition Index and Motivation Subscales of the Behavior RatingInventory of Executive Function - Adult Version (BRIEF-A)
4. Impairment: must have a total score > 95th percentile on the Barkley Functional Impairment Rating Screen (Barkley Functional Impairment Scale (BFIS).
5. For the Sluggish Cognitive Tempo - group, < 5 items on the Barkley SCT Scale must be rated 3 ("often") or 4 ("very often") and total SCT symptom score < 26; must have a T-score < 65 on the Metacognition Index and Motivation Subscales of the BRIEF-A.

Exclusion Criteria:

1. Meets DSM-IV-TR criteria for a primary diagnosis of hyperactive-impulsive type ADHD.
2. Any other current psychiatric disorder, determined via the M.I.N.I , which requires pharmacotherapy treatment.
3. Current suicidal ideation or history of suicide attempts, based on the Columbia- Suicide Severity Rating Scale(C-SSRS).
4. Lifetime history of bipolar disorder or any psychotic disorder as per the M.I.N.I
5. Pregnant, breastfeeding or women planning to become pregnant.
6. Positive urine drug toxicology are excluded.

11 weeks

The intent of the study was to evaluate "the two different sequences" (that is, to compare the order of Lisdexamfetamine treatment) rather than to compare "Lisdexamfetamine" to "Placebo". Therefore, data was not collected and reported for Placebo.