People have always wondered why moods change with the seasons. The effect on mood is not actually attributed to the seasons, but on the amount of light received throughout the different parts of the year. While some people can easily adjust to the changes in lighting, some do not.

The pathologic condition associated with seasonal light changes is known as seasonal affective disorder (SAD). It is a mood disorder that is manifested by symptoms of depression during certain times of the year, particularly in winter. Seasonal affective disorder is not exclusive to people who have had previous mental illness; it can affect normal people as well. The incidence of SAD varies with geographic location, and it is more prevalent in the northern and southern hemispheres.

Light does have an effect on a person’s mood. The amount and wavelength of light affects the different functions of the brain, including the regulation of a person’s thoughts and feelings. With this knowledge comes a realization that simple adjustments in lighting in homes and offices can make a lot of difference to the way a person thinks and feels. Having this in thought, wouldn’t it be equally right to advice a depressed person to “get some light?”