Sleep problems in early childhood may be linked to the development of certain mental health disorders in adolescence, according to a new research.
A study of 7，155 children in the United Kingdom found that waking up frequently during the night and irregular sleep routines as babies and toddlers was linked to psychotic experiences in children ages 12 and 13. Also, children who slept for shorter periods at night were more likely to be associated with borderline personality disorder at ages 11 and 12.
The research,which published in the journal JAMA Psychiatry,was the first time possible links between early childhood sleep problems and adolescent psychotic experiences and borderline personality disorder（BPD） symptoms have been examined.
"We know from previous research that persistent nightmares in children have been associated with both psychosis and borderline personality disorder," said lead author Isabel at the Institute of Mental Health at the University of Birmingham.
"But nightmares don't tell the whole story. We've found that, in fact, a number of behavioral sleep problems in childhood can point towards these problems in adolescence," she said.
Adolescence, typically defined as the ages between 10 and 19，is a key period in human development because of brain and hormonal （荷尔蒙的） changes, and it is now thought to be when many mental health problems start.
Prior research in Australia found that babies with persistent severe sleep problems in their first year were at greater risk for anxiety and emotional issues in later childhood. Sleep problems in children and adolescents have been shown to predict the development of various emotional and behavioral problems,including depression, anxiety, attention-deficit hyperactivity disorder （ADHD， 多动症），risk-taking and aggression. However, findings have been inconsistent, especially when based on objective measurements of sleep,rather than parental reports.
Sleep and mental health are closely connected in adults,with sleep problems increasing the risk for developing particular mental illnesses as well as resulting from mental health issues.



What can we know from paragraph 3？ ______

A. Childhood sleep problems probably cause youth mental health problems.
B. Severe sleep problems in childhood lead to emotional issues.
C. Persistent nightmares in children are closely related to psychosis.
D. The research has not been known to the public.

What does "it" refer to in paragraph 6？ ______

A. Adolescence.
B. Key period.
C. Human development.
D. Hormonal change.

According to the Australian research, older children who had long-term serious sleep issues at one year old are more likely to ______ .

A. grow slowly
B. develop ADHD
C. do badly in lessons
D. suffer from anxiety

Which of the following can be the best title for the text？ ______

A. A Study About Childhood Sleep Problems Is Under Progress
B. Pay Attention to Children Who Lack Sleep
C. Childhood Sleep Issues Linked to Adolescent Mental Health Problems
D. How to Help Children Develop a Good Sleep Habit