| Active, not recruiting | 4 | 288 | Europe, US | Guanfacine hydrochloride (TAK-503), Intuniv, SPD503, Atomoxetine hydrochloride, Placebo | Shire, Takeda Development Center Americas, Inc. | Attention Deficit Hyperactivity Disorder | 06/27 | 06/27 | | |
| Active, not recruiting | N/A | 20 | Europe | Lisdexamfetamine dimesylate, Vyvanse (Shire Pharmaceuticals Ltd.), Guanfacine Extended Release Oral Tablet, Intuniv (Shire Pharmaceuticals Ltd.), Placebo | King's College London, Shire | ADHD | 12/22 | 03/25 | | |