<p>According to a new study, getting less than nine hours of sleep in a day leads to cognitive impairment, mental problems and less grey matter in brain regions.</p>.<p>As per a study published in the Lancet Child & Adolescent Health journal, elementary school-age children who get less than nine hours of sleep per night have significant differences in certain brain regions responsible for memory, intelligence and well-being compared to those who get the recommended nine to 12 hours of sleep per night, according to a new study led by University of Maryland School of Medicine (UMSOM) researchers.</p>.<p>Such differences correlated with greater mental health problems, like depression, anxiety, and impulsive behaviors, in those who lacked sleep. Inadequate sleep was also linked to cognitive difficulties with memory, problem-solving and decision making. The findings were published today in the journal. The American Academy of Sleep Medicine recommends that children aged 6 to 12 years of age sleep 9 to 12 hours per night on a regular basis to promote optimal health. Up until now, no studies have examined the long-lasting impact of insufficient sleep on the neurocognitive development of pre-teens.<br /> </p>