Summer SAD: Causes & Symptoms

Seasonal affective disorder (SAD) is a type of depression triggered by seasonal changes, typically occurring with the onset of autumn. It affects around 1% to 2% of the population, particularly women and young individuals, while a milder form of winter blues can impact approximately 10% to 20% of people.

Although winter is commonly associated with SAD, certain individuals face greater challenges during warmer weather.

There is a less common variant of SAD known as "summer depression," which emerges in late spring or early summer and persists until fall.

Experts explore various specific theories to elucidate the causes of summer depression. A prominent theory posits that excessive exposure to sunlight during the summer months disrupts the body's internal clock or circadian rhythm, leading to reduced levels of melatonin. Consequently, individuals with summer SAD may experience insomnia or other sleep disturbances.

Some studies have indicated a potential link between summer SAD and higher temperatures and humidity.

Individuals grappling with summer SAD may exhibit the following symptoms:

~Agitation and restlessness.
~Anxiety.
~Decreased appetite and weight loss.
~Episodes of violent behavior.
~Trouble sleeping (insomnia).
Summer SAD: Causes & Symptoms

Winter SAD (Seasonal Affective Disorder)

In most cases, SAD symptoms start in the late fall or early winter and go away during the spring and summer; this is known as winter-pattern SAD or winter depression. Seasonal pattern disorders occur most frequently in winter although they can also occur in summer.

People with seasonal affective disorder have difficulty regulating the neurotransmitter serotonin, a neurotransmitter believed to be responsible for balancing mood.

Among the symptoms of winter depressive disorders:
*Feeling depressed most of the day, nearly every day
*Feeling sluggish or agitated
*Hibernation reflex
*Daytime fatique
*Craving foods with lots of sugar like cakes, candies, and cookies
*Weight gain by eating extra carbohydrates
*Hopeless, feeling less motivated and feeling withdrawn
*Losing interest in activities once enjoyed before
*Heavy feeling in arms and legs
* Having difficulty concentrating
*Having frequent thoughts of death or suicide

*Having problems with sleep. Sleeping too much, or difficulty waking up (common with SAD in winter)

Some people with winter SAD seem to produce higher levels of melatonin and lower level of serotonin during winter. Melatonin is a hormone produced by the pineal gland that responds to darkness by causing sleepiness.

At night, a tiny gland in the brain produces a chemical called melatonin, which helps the person sleep. Shortened daylight hours in winter can alter this natural rhythm and lead to SAD in certain people.

With less outdoor exposure to sunlight on the skin in winter, people with SAD may produce less Vitamin D. As Vitamin D is believed to play a role in serotonin activity, Vitamin D deficiency and insufficiency have been associated with clinically significant depressive symptoms
Winter SAD (Seasonal Affective Disorder)
Updated version

Hormone melatonin in seasonal affective disorder (SAD)

Seasonal affective disorder or SAD is a type of recurring major depression with a seasonal pattern. The exact cause of SAD is not fully understood, but it is thought to be linked to reduced exposure to sunlight during the shorter days of the year.

Seasonal affective disorder is commonly known as seasonal depression or the “winter blues.” It is a subtype of major depression that occurs due to changes in climate and seasonal weather. Sunlight plays a critical role in the decreased serotonin activity, increased melatonin production, disrupted circadian rhythms, and low levels of Vitamin D associated with symptoms of SAD.

People with SAD may also have difficulty with overproduction of melatonin. Melatonin is a hormone produced by the pineal gland that responds to darkness by causing sleepiness. Melatonin promotes calmness and relaxation, helping individuals rest their bodies and minds in order to fall asleep

Melatonin is a hormone produced in the pineal gland in the brain. Its production is controlled by body’s master clock, found in the suprachiasmatic nucleus.

During the day, hormone melatonin levels are low. But as it gets dark, optic nerves send signals to the master clock, which signals the brain to begin producing melatonin.

People who suffer from SAD may overproduce melatonin, causing them to feel sleepy and lethargic during the day. This is common for people who experience SAD in the winter.
Hormone melatonin in seasonal affective disorder (SAD)

What is summer depression?

In the United States, summer depression is only about one fifth to one quarter as common as SAD (seasonal affective disorder).

Individuals with summer depression present a picture opposite to that of patients with winter depression.

Rather than an anergic, hyperphagic, hypersomnic, depressive picture, patients with summer depression presented with an agitated, hypophagic, hyposomnic, depressive clinical picture.

The patient will probably lose his appetite and some weight, have trouble sleeping, and feel anxious.

In addition, people with summer SAD report more suicidal ideas than their winter counterparts and may be at greater risk for harming themselves or taking their own lives.

Heat may be the triggering environmental factor in summer depression.
What is summer depression?

SAD of Winter depression

Hippocrates noted that some people adapt well and some poorly to the summer and that same applies to the winter. Winter depression was identified in the early 1980s and observed primarily in women.

Winter depression is a type of despondency that returns year after year during the winter period. Its symptoms appear in the autumn, and abate in the spring when the hours of daylight increase. Light treatment has been used with benefit for this disorder.

Among the symptoms of winter depressive disorders:
*Oversleeping and more deeply
*Hibernation reflex
*Daytime fatique
*Craving carbohydrates
*Weight gain by eating extra carbohydrates
*Irritability
*Hopeless, feeling less motivated and feeling withdrawn
*Heavy feeling in arms and legs
*Suicidal thoughts, also may be present

Women appear to be most susceptible to winter depression and the symptoms usually appear between the ages of 20 and 30.

Winter depression is also called SAD (Seasonal Affective Disorder). The risk of winter depression is increased in gloomier climates and in the northernmost latitudes.
SAD of Winter depression 

What is Seasonal affective disorder?

Seasonal affective disorder (SAD) is a type of depression that comes and goes as seasons change. The most prevalent form of SAD arrives in the fall and winter and lifts during the spring and summer.

Most scientists believe that the primary cause of SAD is diminished sunlight that accompanies the shorter days in the winter.

For many people, reduced light triggers changes that reverberate throughout their bodies and minds causing their moods to darken.

It has been hypothesized that the circadian hormone melatonin is involved in SAD. Melatonin is a hormone that aids the body in sleeping.

Melatonin is a ‘night’ signal released from the pineal gland, which activates M1 and M2 receptors found in the brain clock, the suprachiasmatic nucleus (SCN), and which modulates the circadian rhythm generated by the clock.

Light inhibits the activity of hydroxytryptamine-o-methyltranferase, which coverts serotonin to melatonin. Without adequate sunlight, serotonin may be lost by being converted to melatonin.
What is Seasonal affective disorder?