There is an undeniable association between stress and sleepless nights. Most people have first hand experience of this but what is less clear is whether the stress we experience in early life has an effect on sleep later in life. Alice M. Gregory and Nicola L. Barclay, two British psychologists, have attempted to answer this question by reviewing literature from a variety of studies.

One source of material came from the Dunedin study. This is a long running study of 1037 people born in...