Seasonal affective disorder (SAD), also called winter depression, winter blues, and seasonal depression, is a mood disorder subset in which people who have normal mental health throughout most of the year exhibit depressive symptoms at the same time each year, most commonly in the winter.

SAD is a type of depressive disorder, and sufferers may exhibit any of the associated symptoms, such as feelings of hopelessness and worthlessness, thoughts of suicide, loss of interest in activities, withdrawal from social interaction, sleep and appetite problems, difficulty with concentrating and making decisions, decreased sex drive, a lack of energy, or agitation. Symptoms of winter SAD often include oversleeping or difficulty waking up in the morning, nausea, and a tendency to over eat, often with a craving for carbohydrates, which leads to weight gain.

There are several theories as to the cause of SAD, all of which relate to the effect of light on the brain: lack of sunlight leads to a higher level of a chemical, melatonin, which slows the body down. Hibernating animals secrete high levels of melatonin in order to sleep through the winter months. Another theory sug­gests the condition is caused by a disturbance of the dopamine and serotonin levels in a particular part of the brain, known as the hypothalamus. This area controls mood and appetite – for life, for food and for sex. Some researchers believe that sufferers of SAD have lower eye sensitivity to light. All three theories may be true. The eye sensitivity to light will affect the hormone levels, as the eye is essentially highly evolved nervous tissue.

Although these theories may serve to explain the mechanisms at play, there is still the unanswered question as to why some individuals are more susceptible to depression than others. Since homeopathy looks at the whole person, rather than a list of their symptoms, it is uniquely placed to help with depressions of all types, including those that exhibit periodicity.

Remedies can be thought of for SAD:

AURUM MET: THE GOLD , Gold the metal , this remedy is made from the the metal Gold.

Melancholy, with inquietude and desire to die. Irresistible impulse to weep. Imagines he has lost the affection of his friends; this makes him weep. Sees obstacles everywhere. Hopeless. Sad, feels that all is against him and life is not desirable, and the thought of death alone gives pleasure. When melancholic the patient loses every interest in life. Everything seems to him futile meaningless, sad. He wants to end his life. He feels that he is to blame for everything, that he has made mistakes, that he has neglected his duties, that his friends have lost their trust in him. He feels deep despair and wishes to give an end to his life.

Great anguish, which even induces a disposition to suicide. Excessive anxiety of conscience. Despair of oneself, and of others. The least contradiction excites his wrath. Alternate peevishness and cheerfulness.

PHOSPHORUS: has a really close relationship with the weather, loving the sun and sparkling with it - actually feeling invigorated by being out in the sunshine. They are deeply affected by cloudy weather - becoming miserable and gloomy the longer the sun stays away. In the deepest, darkest time of the winter they can slow right down, not wanting to do anything. Chocolate is their great source of comfort at those times - as are their friends. Even brief outbursts of sunshine on a winter's day will lift their spirits, as can getting out with friends and going to a party or going dancing!

AMMONIUM CARBONICUM : is for chilly individuals who are very much affected by the dull, cloudy weather of winter - they become apathetic and unmotivated, not wanting to work or do anything. They eat themselves silly - craving lots of sweet things (especially candies which give them toothache) - and they put on lots of weight. Ill-humour in the morning, and when it is bad weather. Great absence of mind and weakness of memory.─Tendency to make mistakes in speaking, in writing, or in calculating.─Impairment of the intellectual faculties.

RHUS TOX : This remedy is useful for those who are particularly vulnerable to cloudy weather, who find that the cold, damp, wet, and cloudy weather makes them feel just plain miserable. Their body reacts by stiffening up-especially the back and the joints-which makes them feel even worse. Getting up after sitting or lying down for a while is difficult, and then continued movement eases the stiffness. Unfortunately those joints start to hurt again after being used for a while so the person has to rest-after which the whole maddening cycle starts again, thereby causing the restlessness that is a keynote for this remedy.