Distractibility

Distractibility is a core and characteristic symptom of Attention-deficit/Hyperactivity Disorder (ADHD). It can significantly impact a person's performance and behavior in the classroom, at work, at home, and in social interactions with peers. Distractibility is more predominant in people who exhibit symptoms of attention deficit, but it can also influence the behavior patterns of people with hyperactivity disorder. 

The most common symptoms of distractibility are:

1. Difficulty controlling attention. Finding it challenging to sustain focus in tasks that require prolonged mental effort. 
2. Easily sidetracked by extraneous stimuli, often switching from one activity to another, a significant barrier to sustained focus and concentration. 
3. An inability to stay still, talk excessively, and display disruptive behaviors in structured environments like classrooms or offices. 

Distractibility complicates the ability of a person who displays symptoms of both inattention and hyperactivity-impulsivity to focus. This may be due to both attentional deficits and the internal restlessness that stems from hyperactivity. It isn't limited to just one or the other but can be influenced by both attentional deficits and hyperactivity and acts as a bridge between them.