SAD (Seasonal Affective Disorder) is a type of winter depression which affects millions of people every winter between September and February, in particular during the months from September through to March or even later depending on light levels and is recognised by Doctors and Psychiatrists as a medical condition . Symptoms include a general feeling of gloom and misery, a lack of interests in normal social activities and an overall feeling of depression for no obvious reason. Some people refer to S.A.D. as Seasonal Affected Disorder or SAD Disorder.
S.A.D. symptoms may be accompanied by a craving for carbohydrates and sweet foods, often resulting in unwanted weight gain, adding to SAD depression. Sufferers find that they can sleep longer but wake up feeling tired and gain no benefit from the extra sleep. Very often, SAD is a disregarded illness, with sufferers putting their symptoms down to the 'winter blues'. However Sad Disorder can be an extremely debilitating condition.
SAD is caused by a biochemical imbalance in the hypothalamus due to the shortening of daylight hours and the lack of sunlight in winter. For many people SAD is a seriously disabling illness, preventing them from functioning normally without continuous medical treatment. For others, it is a milder condition, causing discomfort and find they eat and sleep slightly more in winter and dislike the dark mornings and short days and this is commonly referred to as sub-syndromal SAD or winter blues. It is estimated that a staggering half of the UK population have this milder form of condition. There is also a rare reverse form of SAD, known as summer SAD, where symptoms occur each summer and remit in winter.
In the beginning man only worked and lived outdoors in full natural daylight. At the turn of the 19th century 75% of the population worked outdoors. Now less than 10% of the population work in natural outdoor light. This change has resulted in a dramatic increase in light deficiency symptoms.
This can affect many teenagers and adults alike who have trouble in getting up in the mornings for school or work and then feel tired, stressed or depressed.
The symptoms of SAD can vary from person to person, and are similar to those that develop in other types of depression. For more information, see Related topics. The most common symptoms include:
Sleep problems - a desire to oversleep and difficulty staying awake, cannot get out of bed, needing a nap in the afternoon, disturbed sleep and early morning wakening;
Overeating - a craving for carbohydrates and sweet foods, usually resulting in weight gain
Social problems - irritability and desire to avoid social contact
Loss of Libido - a decreased interest in sex and physical contact
Lethargy - too tired to cope, fatigue, often incapacitating, making it very difficult or impossible to carry out normal routines
Physical symptoms - often joint pain or stomach problems, lowered resistance to infection
Cognitive Function - Difficulty with concentration and memory, the brain does not work as well, or as quickly
Depression - Low mood, worse than and different from normal sadness, misery, guilt, loss of self-esteem, negative thoughts and feelings sometimes hopelessness and despair, apathy and inability to carry out normal routine
Anxiety - Tension, Stress is harder to deal with especially in young people
Sudden Mood Changes in Spring - Sharp change in mood, Some experience agitation and restlessness and/or a short period of hypomania (over activity), no dramatic mood change but a gradual loss of winter symptoms
One of the most important distinguishing features of SAD is that it is highly seasonal. SAD symptoms usually reoccur regularly each winter, starting between September and November and continuing until March or April; a diagnosis can be made after 2 or more consecutive winters of symptoms. In sub-syndromal SAD, symptoms such as tiredness, lethargy, sleep and eating problems occur, but depression and anxiety are absent or mild.
SAD symptoms disappear in spring, either suddenly with a few weeks of hypomania/hyperactivity, or gradually, depending on the intensity of sunlight in the spring/early summer. In summer SAD, symptoms may be related to excessive heat rather than light and may include irritability and lethargy rather than oversleeping and overeating.
What Causes S.A.D
SAD is related to changes in the amount of daylight during the autumn and winter. Researchers have proved that bright light makes a difference to the brain chemistry but why some people suffer and others don't is not clear.
Scientists and doctors worldwide have been researching SAD since the early 1980s, and there are several different theories as to what causes it and where the problem lies. They mostly centre on the way that light triggers messages to part of the brain called the hypothalamus, which controls sleep, mood and appetite.
Low serotonin levels
Neurotransmitters (brain chemicals) carry the messages to the brain. There are several neurotransmitters involved in SAD, but the main one is serotonin. Levels of serotonin have been found to be lower in depressed people, in winter. It's thought that this neurotransmitter might not work properly in people with SAD.
High melatonin levels
After reaching the hypothalamus, nerve impulses travel to a tiny organ behind it called the pineal gland. While it's dark, the gland produces the hormone melatonin, which makes us sleep. Light stops melatonin production, so we wake up.
People with SAD have been found to produce much higher melatonin levels in winter than those who don't have SAD symptoms, but their summer levels are normal. When treated with bright light, melatonin levels drop to normal. However, suppressing melatonin doesn't cure the symptoms, so this factor isn't likely to be the sole cause of SAD.
Disrupted body clock
The suprachiasmatic nucleus (SCN), in the hypothalamus region of the brain, sets a person's body clock (circadian rhythm) by 'noticing' when it's daylight or not. One theory is, that if it becomes 'faulty' it can slow down the body clock, causing lethargy and depression. However, bright light (in the morning or from light treatment) can 'reset' the body clock and alleviate the symptoms, so the faulty SCN can't be the only factor involved in this ongoing disorder.
No one really knows what triggers SAD, but it has been linked to events such as childbirth, hysterectomy or other hormonal upheavals. It's been suggested that postnatal depression may be SAD, brought on by the considerable stress of having a baby. Note: if you already suffer from SAD, and are hoping to start a family, spring is probably the best time to have a baby.
SAD has also been reported to have been triggered by a major loss or bereavement, or by serious illness, all of which are common triggers of depression.
· SAD shows no discrimination.
· It affects everyone without any regard to class, race or occupation.
· It occurs throughout the northern and southern hemispheres but is rare in those living within 30 degrees of the Equator, where daylight hours are long, constant and extremely bright.
· SAD affects both sexes. But it was found to affect women more than men.
· SAD may begin at any age, but the main age of onset is 18-30. Children and adolescents are also vulnerable
· SAD may be hereditary. Many SAD sufferers come from a family where a parent or a close relative suffer from SAD.
· In U.K, Europe, Australia and Canada, doctors estimate that five percent of the population suffer from SAD. It is estimated that ten percent of the population in the USA suffer from SAD. Across the world the incidence increases with distance from the equator, except where there is snow on the ground, when it becomes less common.
Children with Seasonal Affective Disorder
Children with SAD often suffer from fatigue and irritability, but not necessarily depression. They are generally aware that something is wrong, very often, they will blame their problem on external factors such as someone is "picking on them" Usually, these symptoms are thought to be the result of the onset of puberty or of adolescence. Keep an eye on your children to see whether they experience a seasonal decline in academic achievement, activity or mood.
Almost all children with SAD suffer the following symptoms during the autumn and/or winter months:
Some will show symptoms such as:
· Sleep problems, disturbed sleep, tendency to fall asleep during the day
· Increase in appetite
· Carbohydrate or junk food cravings
Keep an eye for the following tell-tale signs of the performance at school:
· Decline in academic achievements
· Loss of desire to take part in activities, especially sports
· Memory impairment
· Poor organizational skills
· Difficulty in writing
Children suffering from SAD may also show behavioural difficulties such as:
· Withdrawal from family and friends
· Crying spells
· Temper tantrums
· Tendency to watch a lot of television without retaining what is seen
· In springtime become hypomanic with feelings of elation, talkativeness, sleepless nights and hyperactivity.
Children suffering from SAD is treated the same way as adults
Diagnosis of SAD
Your GP is a good first point of contact. He or she will ask about your day-to-day life and symptoms. One bout of the "winter blues" doesn't automatically mean you have SAD. But, if you have regular symptoms over three or more consecutive years in autumn/winter which clear in the spring, the diagnosis may be SAD.
Your GP may also want to rule out other forms of depression.