Accordingly, society should make distinctions between those suffering conventional brain diseases like Alzheimer's and multiple sclerosis and the disorder of addiction.

For around a decade, scientists have been trying to regrow nerve cells lost in neurodegenerative diseases such as Parkinson's, Alzheimer's and amyotrophic lateral sclerosis (ALS) from stem cells.

Professor Benedict also said his study could support previous studies which linked a lack of sleep with increased risk of Alzheimer's, Parkinson's and multiple sclerosis.