Some people feel low during winter season. A recent research has found association between seasonal changes and brain activity. The team of researchers led by Nicole Praschak-Rieder and Matthaeus Willeit of Canada's Centre for Addiction and Mental Health in Toronto found out that winter season can be gloomy for some people due to low-sunlight surge of brain protein.

Researchers analyzed the data collected from the brain scans of the 88 adults carried out in different seasons. The brain scans of study subjects during summer and spring seasons were compared with brain scans done in the fall and winter seasons. Researchers found out that the presence of high levels of a protein during the fall and winter season. This particular protein interferes with the work of serotonin. Serotonin is known as mood elevating chemical. It relays signals from nerve cells regulating sleep, energy, mood, appetite and mating. Low levels of serotonin can cause depression or anxiety.

According to statistics of the American Academy of Family Physicians, arrival of winter season depresses nearly a million people in the U.S. The study showed that along with mild changes in mood, the body produces more of a protein called serotonin transporter during darkness that sweeps serotonin from the brain.

Researchers said that these findings have important implications for understanding seasonal mood change in healthy individuals, vulnerability to seasonal affective disorder, and the relationship of light exposure to mood. They added that these fluctuations may explain ``lack of energy, fatigue, overeating, and increased duration of sleep during the dark season.''