Beijing, China - Medical researchers claim they may have discovered the youngest case of Alzheimer's disease, challenging the conception that the disease only occurs in the elderly.

According to a recent study published in the Journal of Alzheimer's Disease by researchers from Capital Medical University’s Xuanwu Hospital, a 19-year-old has been diagnosed with probable Alzheimer’s disease after two years.

The study, led by Jia Jianping of the hospital's Innovation Center for Neurological Disorders, focused on early-onset Alzheimer’s disease in young people, which the researches say poses "one of the most challenging scientific questions of the future."

At 17, the patient began having issues with short term memory loss, forgetting small details such as where he left his belongings, and gradually bigger details such as the events of the previous day.

His concentration also declined, causing delayed reactions to specific stimuli and difficulties with reading and other basic daily activities.

Over the course of the two-year study, the patient's condition gradually worsened, eventually meeting the criteria for diagnosis at 19.

Researchers noted that this particular patient's case is unique as they did not find any "recognized genetic mutations" of the disease within him, nor did he have a family history of Alzheimer's.

In January, Jianping and his team also published a study in the British Medical Journal claiming a healthy diet, cognitive activity, and physical exercise all have the "strongest protective effect on memory" loss.