Until now, it has been assumed that people with conditions like ADHD, Tourette syndrome, obsessive compulsive disorder and schizophrenia -- all of whom characteristically report symptoms of "brain clutter" -- may suffer from anomalies in the brain's prefrontal cortex. But a researcher has brought new hope to these patients. He believes the key to the "brain clutter" and impulsivity shown by individuals with dysfunctional prefrontal cortices lies in a malfunction of a specific type of brain cell.