Mood swings at night
Animals who are exposed to light at night suffer moods that are found in sufferers of depression. For those who are undergoing therapy to treat depression, getting sunlight will help them.
Researchers believes that individuals undergoing such treatment with chronic exposure to night light will also suffer.
Studies of individuals who work night shifts confirms the observations made. Richard Stevens of the University of Connecticut Health Center in Farmington has been involved with this study. Cancer, obesity, and diabetes are common ailments now in our daily lives, but apparently mood disorders are also joining this list.
In the new Molecular Psychiatry, three researchers, Tracy Bedrosian, Zachary Weil and Randy Nelson of Ohio State, worked with hamsters to further study the issue. Using a light and dark exposure cycle for four weeks, half the animals had normal light cycles, while others had dim light throughout their night cycles.
Animals that had this chronic exposure to dim lights at night had an increasing preference to sugary drinks. Researchers believe that this is due to a decline in happiness. Along with this, hamsters were then placed in pools of water which they had to escape. Those exposed to night light often just stayed within the water, ignoring the chance to exit.
The scientists examined the brain structure, noticing that the hippocampus of the hamsters within the night light group had less nerve-cell protrusions known as dendritic spines. These spines reductions “are consistent with what we see in humans with major depression,” Bedrosian says.
Returning the animals to a normal light cycle, however, saw recovery beginning as fast as within two weeks. If there could be further research done on human beings, scientists thinks that biological clock affected by light at night can be “an extremely potent force in regulating biology and behaviour.”