Serotonin and SAD

Serotonin is a chemical which occurs naturally in the brain and it's one of the ten main neurotansmitters which help your brain cells (or neurons) talk with each other. Serotonin helps create a feeling of calm, control, confidence and well-being. Patients with seasonal affective disorder generally have low levels of this feel-good chemical in winter.

But what causes low serotonin levels and what decreases serotonin levels in SAD patients in particular?

Levels of serotonin decrease in winter in the general population. It has also been shown that they vary depending on the amount of sunlight on any particular day. It seems there are reasons why we all feel more cheerful on a sunny winter day than on a gloomy, overcast day linked to our serotonin levels.

People with SAD are thought to be especially sensitive in their reaction to these changes in levels of sunlight and serotonin. As a result many of the treatments designed to help those with seasonal affective disorder are designed to raise serotonin levels in the brain.

1. Light therapy

Treatment with a light box of 2,500 to 10,000 lux has been shown to help with SAD symptoms in at least 75% of cases and it's thought that this is due to the influence of that intensity of light on serotonin transmitters.

2. Medication

SSRI anti-depressants such as Prozac, Zoloft and Celexa are often used successfully in the treatment of seasonal affective disorder because they work to increase the levels of serotonin  

3. Diet

Carbohydrate rich meals have been show to raise serotonin levels. (See What Makes Serotonin?). While lack of serotonin may cause cravings in SAD patients, diet can be carefully managed and balanced to provide the required carbohydrates without resorting to sweet and starchy junk food.

With the right treatment or combination of treatments, levels of serotonin can be raised leading to a good outcome for most patients with seasonal affective disorder in bringing symptoms under control.