Mood and sleep problems in adolescents and young adults: an econometric analysis

Sleep related problems affect approximately 25-40% of children and adolescents. The acquisition of sleep patterns characterised by later bedtimes, insomnia and excessive daytime sleepiness is related to poorer school performance, daytime drowsiness, physical tiredness and a higher rate of psychiatric illnesses. Many studies have investigated the correlation between sleep and mood in children and adolescents and overall, show a positive association between sleep problems and psychiatric disorders. However, little is known about adolescents' personal perception of their psychological status as it is linked with the occurrence of mood changes and sleep-related problems.

The aim of the study is to explore the impact of variables such as age, gender, education and the perception of their own psychological status (evaluated through suitable questionnaires) on the simultaneous presence of sleep disturbances and affective symptoms in a sample of adolescents. A positive correlation between these two dependent variables signals the need to intervene with proper support programs.

A recursive bivariate probit model has been employed. This method allows us to take into account two dependent dummy variables and to consider the relationship between the two, presuming that one may also influence the other. The analysis has been carried out on a sample of 2,005 adolescents out of a total of 4,000 who declared their willingness to be telephonically interviewed using a questionnaire in two parts designed to obtain information about the participants sleep habits and affective symptoms.

There is a positive correlation between sadness and daytime drowsiness. The estimated joint probability ranging from 5.5% to 9% in girls demonstrates a greater tendency for girls to experience both depression and altered sleep patterns. DISCUSSION AND LIMITATIONS OF THE STUDY: Just as sadness is a key symptom of affective disorders, daytime drowsiness indicates the presence of sleep disorders caused by sleep habits that are likely to evolve into affective symptoms. This assumption is confirmed by the results of this analysis. However, since the interviews were conducted during the years 2003 and 2004, a replication of the analysis would outline whether this evidence is still the same or whether changes in habits and behaviours have intervened to modify substantially this pattern in recent years. As the analysis considers a sample of adolescents living in two southern Italian regions, the study should be replicated in other geographical areas. IMPLICATIONS FOR HEALTH CARE PROVISIONS AND USE: The early detection of affective symptoms in adolescents may presumably lead to a diminished use of antidepressants and an improvement in learning abilities and school results along with strengthening of personal motivations.

Counselling and educational programs directed towards those adolescents demonstrating poor sleep habits should be planned and implemented to avoid further complications and impact on their mental health.