Use of iron to prepare a composition for preventative and/or curative treatment of attention deficit hyperactivity disorder (ADHD), or at least one of its symptoms, is new. Independent claims are also included for the following: (1) use of iron, combined with at least one psychostimulant (I), for simultaneous, separate or temporally staged use, to prepare a composition for preventative and/or curative treatment of nocturnal and/or diurnal motor hyperactivity and restless leg syndrome； and (2) in vitro prognosis and/or diagnosis (M1) of ADHD by determining the serum concentrations of ferritin and the soluble transferrin receptor. ACTIVITY : Nootropic； Neuroprotective； Tranquilizer； Antiparkinsonian； Anticonvulsant. No details of tests for these activities are given. MECHANISM OF ACTION : Replenishment of low iron reserves.
