Seasonal affective disorder (SAD) is a type of depression that's related to changes in seasons — SAD begins and ends at about the same times every year. If you're like most people with SAD, your symptoms start in the fall and continue into the winter months, sapping your energy and making you feel moody. Less often, SAD causes depression in the spring or early summer.

Symptoms specific to winter-onset SAD, sometimes called winter depression, may include:

• Irritability
• Tiredness or low energy
• Problems getting along with other people
• Hypersensitivity to rejection
• Heavy, "leaden" feeling in the arms or legs
• Oversleeping
• Appetite changes, especially a craving for foods high in carbohydrates
• Weight gain

The specific cause of seasonal affective disorder remains unknown. Some factors that may come into play include:

• Your biological clock (circadian rhythm). The reduced level of sunlight in fall and winter may cause winter-onset SAD. This decrease in sunlight may disrupt your body's internal clock and lead to feelings of depression.
• Serotonin levels. A drop in serotonin, a brain chemical (neurotransmitter) that affects mood, might play a role in SAD. Reduced sunlight can cause a drop in serotonin that may trigger depression.
• Melatonin levels. The change in season can disrupt the balance of the body's level of melatonin, which plays a role in sleep patterns and mood.

Lifestyle changes:

 Massage therapy

Virtually every symptom listed by the American Psychological Association can benefit from massage. Research has shown that it can lower your heart rate and blood pressure ,relax your muscles and increase the production of endorphins, your body's natural "feel good" chemical. Serotonin and dopamine are also released through massage, and the result is a feeling of calm relaxation that makes chronic or habitual as well as acute or short-term stress much easier to overcome

Meditation increases grey matter concentration in the brain

A group of Harvard neuroscientists ran an experiment where 16 people were submitted to an eight-week mindfulness course, using guided meditations and integration of mindfulness into everyday activities. The results were reported by Sara Lazar, PhD. At the end of it, MRI scans show that the grey matter concentration increases in areas of the brain involved in learning and memory, regulating emotions, sense of self, and having perspective.

 Nose drops of warm sesame oil (3 to 5 drops in each nostril) are effective for relieving depression. Do this nasya procedure morning and evening on an empty stomach.

 addition to your treatment plan for seasonal affective disorder, try the following:

• Make your environment sunnier and brighter. Open blinds, trim tree branches that block sunlight or add skylights to your home. Sit closer to bright windows while at home or in the office.
• Get outside. Take a long walk, eat lunch at a nearby park, or simply sit on a bench and soak up the sun. Even on cold or cloudy days, outdoor light can help — especially if you spend some time outside within two hours of getting up in the morning.
• Exercise regularly. Exercise and other types of physical activity help relieve stress and anxiety, both of which can increase SAD symptoms. Being more fit can make you feel better about yourself, too, which can lift your mood.