Tags: Adolescent, Child, Circadian rhythm, DSPS
I don’t think definitive answers are to be found. I’ll offer here my impressions, based on reading and contact with other sufferers.
Adolescent DSPS seems to be a special case. The hormone surge at puberty gives some people all the symptoms of DSPS, even though they didn’t have it before and won’t have it after adolescence. There are activist groups in the USA working for later starting times for high school classes because of this, and they have no trouble finding expert support for their struggles. I’ve even read that teenagers with this problem most often return to their original diurnal preference: cheerful early riser or grumpy late riser. More systematic study would be in order here.
DSPS does not start later than in adolescence except in very unusual cases. Certain brain injuries, tumors or cysts can cause it. I’ve read of one case where acquired hydrocephalus created pressure which caused DSPS. Onset after about age 20 requires a search for a physical cause, if the tumor or injury hasn’t manifested itself already.
In retrospect, the parents of many DSPS sufferers remember that there “always” was something strange about their sleeping patterns. And what infant doesn’t have strange sleeping patterns? Parental memories are colored by knowledge of how their children “turned out”, so any remotely scientific study of those memories sounds to be out of the question. Perhaps it might be possible to search the journals of early childhood clinic visits for mention of sleep problems and compare with later diagnoses of sleep disorders.
A newborn has no circadian rhythm. It is first established at the age of about 4 months.
Usually DSPS appears in early childhood. My intuition would say that it always does, but I’ve discussed this with reliable people who are quite sure that they slept normally pre-puberty.
In sum, the disorder starts in early adolescence or earlier. An adolescent variety may end as adulthood begins. DSPS which hasn’t gone away by one’s mid-20s, is not going to go away. Its nature is not going to change through the years. Its effects on the sufferer will vary according to work schedule, other societal demands, coping strategies and diagnosis/treatment.
The life-long night-owlism.