Claim: One of the members of AC/DC experienced a brain disease called dementia.
Evidence: The band 's line-up remained the same until 2014 with Malcolm Young 's retirement due to early-onset dementia and Rudd 's legal troubles.
Dementia is a broad category of brain diseases that cause a long term and often gradual decrease in the ability to think and remember that is great enough to affect a person 's daily functioning.