Seasonal Affective Disorders (SAD)

A lot of people feel sad or down during winter season, due to the low temperatures and shorter days. For some people this can turn into a subtype of clinical depression that lasts throughout the fall and winter months. This is known as seasonal affective disorder (SAD).

Frequently Asked Questions

  • Recurring, cyclic bouts of depression, increased appetite, increased need for sleep.
  • Contrasts with most depressive disorders, characterised by sleep disturbances, lack of appetite.
  • Mild depression
  • Anxiety
  • Decreased activity
  • Social withdrawal
  • Increased sleep duration
  • Increased appetite
  • Weight gain
  • Carbohydrate craving
  • 10% of general population
  • Most common in people who are treated for depression
  • Most common in higher latitudes, where winter days are a lot shorter than closer to the equator
  • Occurs more in woman than in men
  • SAD may run in families, which suggests that it could be genetic
  • Occurrence of SAD lessons after the age of 55 years
  • 24-hour sleep-wake cycle, circadian rhythm, caused by the rise and fall of hormones–melatonin
  • Melatonin is the master sleep hormone, produced in the pineal gland
  • The sleep-wake pattern, depends on how well the functioning of the internal circadian clock works, deep in the brain.
  • It works with photo sensors in the eyes to sense darkness
  • The body begins to produce melatonin when darkness falls, one of the factors that cause you to sleep.
  • Melatonin is secreted throughout the night, at dawn it decreases and gradually diminishes – causing you to wakefulness in the morning.
  • When there is a problem with this system, sleep disorders and psychological problems can occur.

The Melatonin Theory

  • Studies show that the shorter days in winter led directly to SAD. When researches lengthened the photoperiod by exposing patients to bright light in the morning and evenings. Research was then focused on the secretion of melatonin and the effects thereof. Patients that suffer from SAD had increased duration of melatonin in early hours of the morning. This explains why these people find it difficult to wake up in the mornings. They were given drugs to block melatonin secretion and found that the symptoms of SAD were relieved.

The Phase-shift theory

  • Patients who suffered from SAD had circadian rhythms which had fallen out of sync with the normal cycle.
  • “Phase advanced” when the body releases melatonin to early in the morning.
  • “Phase delayed” when the body continues to release melatonin for too long into the day.
  • This abnormality occurs, with seasonal changes in light exposure where it disrupts normal functioning of the circadian clock.

Retinal hypersensitivity

  • The retinas of people with SAD are more sensitive to light than those of controls, due to the dysfunction of the neurotransmitter. Which means people with SAD are hypersensitive to light.

Neuroimmune dysfunction

  • In winter there is an elevation of the interleukin-6, a pro-inflammatory cytokine, in patients suffering from SAD. These cytokines cause more production of enzymes that deplete tryptophan from the blood. Thus serotonin deficiency in the brain – causing onset of depression. Where decreased levels of tryptophan may lead to an overactive immune system.

Low levels of neurotransmitters

  • People with SAD and other depressive disorders, have low or abnormal levels of neurotransmitters that are important, this includes serotonin, acetylcholine and dopamine. People with SAD have levels of serotonin that vary from season to season, which explain why they crave carbohydrates during the winter season. Because serotonin helps with regulating feeding an satiety. Depending on the rate of production of serotonin in the brain, depends on the length of time you are exposed to bright sunlight, this decreases in the winter months.
  • In depressed patients, a serotonin like drug is given to increase the activation of euphoria in them, but not during the summer months. Change in serotonin levels are also a result of low levels of vitamin D3.
  • SAD patients who are not treated have lower concentrations of norepinephrine, than patients who don’t suffer from this disorder. These reduced levels may lead to hyper insomnia, want to sleep all the time. Low dopamine activity is also common in people who suffer from SAD.

Light therapy

  • Patients are exposed to bright light early in the morning, to reduce the secretion of melatonin, and to stimulate a more natural waking cycle. This has a better therapeutic effect than evening light.
  • Although some patients do not respond due to the side effects or lack of use to this treatment, as it is inconvenient.
  • This treatment is most effective when used in the morning. Device is expensive to use and is not covered by medical aid. The treatment is also time consuming and takes 30-45 min per treatment.

A consultation with one of our health Renewal doctors is needed in order to provide clients with the best way forward. Our Health Renewal doctors travel between branches and are available in the following regions; Pretoria, Johannesburg, Kwa-Zulu Natal and the Western Cape. 

Selective serotonin reuptake inhibitors

  • Fluoxetine and Sertraline -2 antidepressants commonly used in the treatment of SAD. They produce more serotonin to interact with serotonin receptors. Fluoxetine reduces the melatonin levels in these patients, when other antidepressants elevate the melatonin levels. It is important to take these meds in the morning as it is considered the melatonin levels are reduced at the appropriate time.

Selective noradrenaline reuptake inhibitor

  • Reboxitine – The FDA has denied the approval of this drug. Although it is used in the European countries, it has been shown to be effective in treating depression. Side effects are, dry mouth, and constipation mild in intensity.


  • It’s a drug known to promote wakefulness, selectively by influencing the sleep-wake centres of the brain. It is also used in treating narcolepsy and major depressive disorder. It improves wakefulness and reduces fatigue.


  • Is a hormone produced in the pineal gland, and is responsible for regulating sleep and the core body temperature at night.
  • Melatonin levels increase in the evening, before bedtime, and peaks in the middle of the night, and gradually decreases as morning approaches.
  • The excessive duration of melatonin secretion has been implicated, but not yet certain if this is the cause of SAD.
  • Low-dose melatonin is taken at night, has shown to be effective in improving mood in SAD patients.

Nutrient therapy

  • Increases serotonin levels to relieve the symptoms of SAD. Tryptophan is converted to 5-HTP by the enzyme hydroxylase, which may be inhibited by a deficiency of Vitamin B6 or magnesium. 5-HTP is converted to serotonin, and then into melatonin with SAMe which serves as a methylation agent. Nutrients which support healthy levels of tryptophan or promoting healthy methylation help to improve levels of serotonin, to relieve symptoms of SAD.


  • When patients have a deficiency in tryptophan, they do not respond to light therapy. This is needed for the making of serotonin, which is a natural antidepressant. The light therapy stimulates the change of tryptophan to serotonin. Low levels of tryptophan cause high levels of neopterin, combined with low levels of serotonin could worsen depression. This is important to know for patients with autoimmune disorders (arthritis, multiple sclerosis, and Alzheimer’s disease), where the levels of immune system cytokines could already be elevated.


  • It’s the immediate precursor in the making of serotonin from tryptophan. When taken orally is crosses the blood-brain barrier easily and is effective as tryptophan and increasing the levels of serotonin. It is effective in treating insomnia and improving quality of sleep, and also increases cortisol levels. By using this it can result in serotonin syndrome, a condition characterised by agitation, confusion, delirium, tachycardia, diaphoresis, and fluctuations in blood pressure.

Vitamin B6 and SAMe

  • The conversion of tryptophan to 5-HTP may be caused by a vitamin B6 deficiency or magnesium. As well as the conversion of 5-HTP to serotonin, and then converting it to melatonin, depend on SAMe as a methylation agent. Vitamin B6 is important in the production of serotonin. Vitamin B6 deficiency should be considered in people with SAD especially in the elderly who suffer from vitamin deficiencies.


  • Healthy circadian rhythm is associated with normal magnesium levels, which peak in the evening, and fluctuates in the morning. Insufficient levels of magnesium can inhibit the conversion of tryptophan to 5-HTP, and can affect the production of serotonin and melatonin. Magnesium depletion is associated with dysregulation of the biological clock, resulting inan increase or decrease in melatonin in SAD patients.

St. John’s wart

  • Effective in treating symptoms of severe depression and of SAD. It is as effective as light therapy in SAD. St John’s wart effects the uptake and reuptake of MAOIs like serotonin and norepinephrine.

Omega-3 Fatty acids

  • Plays a role in the making of serotonin. People who eat a lot of omega-3 fatty acids in cold water fish, only suffer from SAD rarely. When the fish consumption goes down, there is a definite increase in SAD. Nutrients in fish oil suppress inflammatory cytokines, and alleviate depression. These essential oils have many health benefits, which makes it important to add omega-3 fatty acids to your supplement program.
Sharon Izak Elaine Chat staff ) WhatsApp
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