Washington, September 11: According to studies, persons in their middle years and older should get seven hours of sleep per night, with too little or too much sleep being linked to worse mental and cognitive functioning. Sleep is crucial for maintaining psychological health and supporting cognitive function. It also helps the brain stay healthy by getting rid of the trash. As we age, our sleep patterns frequently change, and we experience issues with falling and staying asleep as well as decreasing quantity and quality of sleep. It is believed that these sleep abnormalities may be a factor in the ageing population's cognitive decline and psychiatric illnesses.