There are several factors to cause depression. Physical exhaustion, psychiatric stresses, poor diet, and some genetic varieties are known as independent risk factors. And also, chronotype seems to contribute to the onset of depression.
The University of Colorado at Boulder and Brigham and Women’s Hospital in Boston gathered over than 30,000 data of nurses to examine the influence of chronotype on depression. As a result, as expected, participants waking at night were likely to become depressive.
Independent: WOMEN WHO WAKE UP EARLY LESS LIKELY TO DEVELOP DEPRESSION, STUDY CLAIMS
In this study, all participants were working nurses. Night shift is well known to be a risk of immature death. Thus, it is possible that the participants had a relatively high risk for depression. This idea makes us difficult to interpret the outcome of this study.
By the way, your pattern of the sleep-wakeup cycle is hard to change. If you are an owl-type person, you are a little likely to become depressive. Then, should you attempt to amend your habit? It depends on your status, in my opinion. If you can wake up early in the morning, do it every day. But if you truly suffer from the binding concept to wake up early, I recommend you to adapt your work style to your chronotype, not the opposite.