Successes and failures in the search for dementia cure

The quest to find a cure for Alzheimer's has led scientists down numerous routes

A scan of an Alzheimer's patient's brain

(Alamy)

Drugs: Some of the biggest drug companies have invested hundreds of millions of dollars seeking a viable treatment. A major blow came in 2012, when Pfizer reported that its drug Dimebon had shown no benefit in trials, costing the company $750m. Unsuccessful trials of two other drugs followed in the same year.

Halting brain cell death: The fundamental cause of mental decline in Alzheimer’s is brain cell death. In 2013, researchers at the University of Leicester halted the process in mice with a drug – a breakthrough which one expert said would be judged by history as a “turning point”. Further studies are ongoing.

Ultrasound: A new technique pioneered in Australia this year uses ultrasound waves to break down plaques in the brain. In mice, this led to improvements in memory, but there are concerns that the complexity of the human brain could mean its functioning might be damaged.