brain disorder
encephalopathy
brain disease

Major depression is the most common form of brain disease.

The cause of his death was given as "organic brain disease."

But I cannot agree with you that much learning breeds brain disease.

Research on this serious brain disease does not, however, support parents' behavior as causation.

He died of brain disease at home in Tignish later that year.

When someone has a brain disease, the main form of treatment is medication.

Knut died on 19 March 2011 because of a brain disease.

In other words, addiction is a brain disease, not a moral failing or behavior problem.

The drug has been linked to a rare but deadly brain disease.

The mental handicap may also be related to brain disease.