Sleep disorders lead to depression

Nearly three quarters of children diagnosed with major depression also experience insomnia, excessive sleeping (hypersomnia) or both. Researchers from the Western Psychiatric Institute and Clinic at the University of Pittsburgh in Pennsylvania found that all sleep problems are not the same for depressed youngsters. Insomnia is the most common problem, but having a combination of insomnia and hypersomnia is double trouble. Differentiating between types of sleep disorders is important in the treatment of depression. The researchers compared the clinical profiles of 533 children treated for major depression at mental health facilities in Hungary between 2000 and 2004. The average age was nearly 12 years and the average illness duration was 14 months. Full diagnostic interviews of the subjects included questions related to difficulty in falling asleep at night, amount of time spent sleeping, sleep quality, difficulty waking up and falling back to sleep, duration of the problem and napping during the day. Conditions were considered significant if they persisted at least 2 weeks. Responses to interview questions showed that nearly 54 percent had insomnia alone, 9 percent had hypersomnia alone, and 10 percent had both. Among those with hypersomnia, more than half also had insomnia. Researchers observed different symptom profiles associated with sleep disturbances. Those with no sleep disturbances had the least severe depression. In general, those with disturbed sleep exhibited greater depressed mood, irritability, sadness, psychomotor agitation, fatigue, inability to gain pleasurable experiences, inappropriate guilt, weight loss, daily variation and anxiety disorders. But this group had less oppositional defiant disorder than those with normal sleep patterns. Insomnia alone was associated with more frequent depressed mood, daily variations, psychological and physical agitation, and feelings of worthlessness, than those with hypersomnia. Children with hypersomnia were more likely to exhibit weight gain or loss, and were also more likely to have been prescribed a selective serotonin reuptake inhibitor (such as Prozac, and tranquilisers). Further work needs to be done, to define the interplay between disturbances in circadian regulation, abnormal exposure to bright light, altered social interactions, and differences in neurobiological mechanisms or genetic causes. Researchers urged paediatricians and parents to pay closer attention to children's moods and problems with sleep, because, ultimately, social functioning could be decreased and the risk of suicide may be increased.