There is evidence of seasonal peaks in suicides, which occur more frequently in summer, and birth rates, which also tend to peak in spring and summer. Both, however, are influenced heavily by other factors, according to a chapter on chronobiology that Provencio contributed to "Comprehensive Textbook of Psychiatry" (Lippincott Williams & Wilkins, 2008).
The strongest evidence of human seasonality comes in the form of seasonal affective disorder, or SAD. Its victims suffer major depressive episodes related to the seasons, usually beginning in late fall or early winter, and remitting in spring or summer.
A 2001 study published in the journal Archives of General Psychiatry found that people suffering from SAD secreted the hormone melatonin for longer periods during winter nights than during summer nights, a fluctuation also seen among mammals whose behavior varies seasonally. Normally, human production of melatonin, which regulates sleep and is called the hormone of darkness, does not vary with the seasons.
In higher latitudes, SAD can affect 10 percent of the population, and it is estimated that as much 20 percent of the population suffers from a lesser form of the disorder, although this is controversial, Provencio said.
Scientists have known that humans and other mammals have an internal clock that governs our sleep-wake cycles, among other daily functions. Light provides us with non-visual cues that influence things like our pupil dilation, alertness, melatonin levels, and heart rate modulation, according to Provencio.
Light receptors in the retina of the eyes – rods, cones and a third type called intrinsically photosensitive retinal ganglion cells – pass along non-visual information used to reset our circadian rhythms.
Everybody's clock doesn't tick on a 24-hour rotation, however. The average human day – as generated by our primary circadian pacemakers, called the suprachiasmatic nuclei and located in the hypothalamus of the brain – lasts about 24 hours and 11 minutes, although it can be longer or shorter for individuals. Light "resets" this internal clock, so our bodies are in synch with the time of day, according to Provencio.
People with a longer natural cycle tend to be night owls; meanwhile, early risers tend to be the morning larks, according to Domien Beersma, head of the chronobiology department of the University of Groningen in The Netherlands. Unfortunately for night owls, they face "sleep inertia" after a late night and less rest than a morning lark, he said.
While other factors, such as locomotion, can influence animals’ internal clocks, humans' rely primarily on light, he said. ..........
Now the amazing thing is that during my Hypnosis sessions with my clients , I use a technique from timeline therapy where i will ask my client to brighten the future, and a big percentage of my clients feel happier immediately as I ask them to brighten the future in front of them just like a brightness button on the computer screen. If you have attended a session with me then you know what i mean when i ask you about the direction and storage of time and ho we encode time in the sub-conscious.
Here is a short practice for your mind which will benefit you immensely
ask yourself which way you point to the future?
now notice how the brightness levels of the future, the now and the past have contrast.
go ahead and make the future the brightest part for the sake of this practice...Notice that it is impossible to have the future bright and to be sad at the same time....the point is that the location that you store info and the encoding about your future, can be tampered with, and you decide how to feel about things based on the brightness levels, and the colors...with that said and done, go ahead and do the same to explore your past..if you see any dark spots or missing memories in the past, then that area needs attention because of abandonment or trauma which yo0ur unconscious is blocking...If you nee help just Email me on this as it is sensitive..
I also highly recommend my Album "Achieving Emotional Freedom" which primarily helps you sort out the black bags of the past and to clear the clutter. This album will help you access your inner child in those pictures of the past and to gain more energy , by releasing the unconscious avoidance events....