Looking at the light is the key - a quick glance every few minutes during the session is necessary for the treatment to work. Those who respond to light therapy may notice that their moods improved as soon as two to four days into the course of treatment. For some people a combination of drug treatment and light therapy may be effective. SAD not only occurs with the onset of winter, but can affect some people in the hot months of summer, according to Shield. It's called Summer Seasonal Affective Disorder.
Heat makes some people instantly depressed.
They respond better to cold. T he science behind SAD involves the regulation of the neurotransmitter serotonin and the hormone melatonin. The latter is secreted at night by the pineal gland, a pea-sized structure at the base of the brain. Melatonin appears to play a major role in regulating the body's circadian rhythms, says Shield. Melatonin also appears to decrease serotonin levels.