Conditional BDNF mice (BDNF2lox/2lox/93), characterized by low BDNF expression in the hippocampus, hypothalamus, and cortex, develop hyperactivity and aggression after stress (19), which supports the role of BDNF in the processing of motor control or in the worsening of hyperactivity symptoms of ADHD. Here, BDNF is linked to attention deficit-hyperactivity disorder.