Seasonal Affective Disorder (SAD)

A Complete Guide to Seasonal Depression


Hannah is the lead writer and editor for Hannah has been writing for since 2020. During this time, she has helped countless people to find happiness in their lives once again.

Many people experience the ‘winter blues’ or seasonal depression at some stage in their lives. For some people, these bouts of depression are much more than an isolated week or two of feeling down. If you note that you start to feel depressed every year, you may be dealing with seasonal affective disorder. 

Seasonal Affective Disorder (SAD) is a major depressive episode that occurs in relation to specific seasons of the year. The most traditional time for SAD is during fall and winter, but some people experience SAD during spring and summer. SAD is a subtype of clinical depression and shares symptoms.

Seasonal affective disorder can cripple your life, and it can be present for as long as five months in the year. That is almost half your year spent in the grip of black depression. There is help available, and different methods can be used according to individual needs and preferences.

Seasonal Affective Disorder
Seasonal Affective Disorder, or SAD, is a type of depression that occurs during certain times of the year, usually winter.

What Is Seasonal Affective Disorder (SAD)?

SAD is a major depressive episode that recurs annually at approximately the same time each year. Depression in SAD lasts for several months or a season and is followed by a period of recovery. 

The most typical form of SAD occurs over the late fall and winter months. Recently psychologists have noted that some people seem to have SAD over spring and summer, but this is rare. 

In prior years many medical doctors and even psychologists dismissed SAD because it seemed to resolve without intervention. They felt that this did not fall into a typical pattern of depression, and therefore, it did not fit the diagnosis for major depression.

In 1984 a psychologist named Rosenthal, who had relocated from South Africa to the United States, noted that he was less productive and experienced lower moods during winter. He completed a study and described Seasonal Affective Disorder in detail. SAD was accepted into the Diagnostic Manual for Mental Disorders (DSM). This was a critical point as the DSM is followed by medical and psychology practitioners globally. 

Finally, everyone who had been suffering for many years with annual depression could be diagnosed. Acknowledgement of their condition validated the individual. Many SAD patients were dismissed and informed that what they were experiencing was not real. 

The diagnosis prompted research into treatment programs which were critical in helping SAD sufferers. Research into treatment protocols is ongoing, and new approaches are being developed.

What Causes SAD?

The causes of SAD have been up for debate, and there is still discussion as to the exact cause or possibly multiple causes. In the next few sections we will begin to some of the potential causes.

Low Vitamin D Levels

Vitamin D is produced by our bodies in the presence of sunlight and plays a crucial role in the production of serotonin. During winter, people stay indoors, wear many layers of clothes when they are outside, and the overall daylight hours are diminished. This all contributes to a potential vitamin D deficiency. 

Low Vitamin D for Seasonal Depression

It can be difficult to tell if SAD patients have low vitamin D, which causes SAD or if their low mood causes them to spend less time outside during winter, which causes low vitamin D. 

Some people produce reduced levels of vitamin D, even in the presence of sunlight. Individuals with low Vitamin D are at risk of developing SAD.

The Role Of Melatonin In Seasonal Depression

A hormone known as melatonin is produced by the pineal gland in the brain. The amount of melatonin produced is influenced by the number of daylight and night hours. During dark hours melatonin is released to make the body feel sleepy. 

In winter, daylight hours are reduced as the sun sets earlier and rises later. As a result, more melatonin is produced, resulting in the individual feeling sleepy and lethargic. People with SAD have an overproduction of melatonin in the winter months

Over production of melatonin can exacerbate the feeling of tiredness in the dark winter months.

You may have observed that even if you do not suffer from SAD, you tend to feel more tired and want to go to bed earlier in the winter months. This is a result of increased melatonin production. While melatonin does not cause SAD, it adds to general feelings of apathy and low mood.

Does Your Circadian Rhythm Affect SAD?

Circadian rhythms are the biological clock that governs our waking and sleeping and are influenced by serotonin and melatonin. People that suffer from SAD have altered serotonin and melatonin during winter, resulting in a circadian rhythm that cannot adjust to the winter light-dark changes. 

Circadian Rhythm

SAD sufferers have circadian rhythms that cannot synchronise with shorter days and longer nights. Although researchers are still not certain of the exact nature of the link, they theorise that when circadian rhythms cannot adjust to seasonal changes, the result is a major depressive episode. 

It is thought that summer SAD may be caused by an inability of the body to adjust to the increased light levels in spring and summer. Not much research has been done on summer SAD, and as a result, the cause is still vague. 

Some psychologists postulate that people who cannot adjust to increased heat and temperature may be vulnerable to mood disorders in these months.

What Are The Symptoms Of SAD?

The symptoms of SAD are very similar to depression. These are some of the symptoms that may be seen:

  1. Low mood and decreased energy.
  1. Loss of interest in previous hobbies.
  1. Inability to feel pleasure or disinterest in pleasurable activities.
  1. Feeling sad and crying easily. The person may often express that they do not know why they are unhappy.
  1. Withdrawal from social activities.
  1. Decreased activity levels that cause further depression as the natural mood boost that comes from exercise is not accessed.
  1. Feeling worthless or experiencing guilt over past events.
  1. Irritability is common in teenagers, children and people that have summer SAD.
  1. Difficulty concentrating.
  1. Hypersomnia – sleeping long hours and, in severe cases, spending concurrent days in bed.
  1. Craving carbohydrates and, as a result, gaining weight. Serotonin is synthesised in response to carbohydrates which is why low serotonin prompts carbohydrate cravings. Carbohydrates act as a natural tranquilliser which causes a psychological addiction to carbohydrates.
  1. Losing weight because of apathy which results in poor motivation to cook or shop. This is less common than putting on weight due to carbohydrate cravings, and it is seen more commonly in summer SAD.
  1. Suicidal ideation – thoughts of suicide. The individual may or may not express this to a therapist, friend or family member.

It is critical to note that every person experiences SAD in a unique way. SAD sufferers seldom have all these symptoms. The DSM-V criteria for a diagnosis of SAD states that five symptoms should be present for two weeks. One of the symptoms should be a depressed mood or disinterest in pleasurable activities.

Some people have a milder form of SAD, known as subsyndromal SAD (S-SAD). The person exhibits similar symptoms but with less intensity. Medical personnel or laypeople sometimes refer to this as ‘winter blues’.

How Is SAD Diagnosed?

SAD is diagnosed by a psychologist, psychiatrist or medical doctor. Rosenthal developed a screening tool known as the Seasonal Pattern Assessment Questionnaire (SPAQ). This may be used to identify at-risk individuals. 

A full assessment by a psychologist or psychiatrist will determine if SAD is present. Medical doctors may also diagnose SAD by comparing symptoms to those described in the DSM-V. 

The medical professional will take a complete history and conduct blood tests to rule out other underlying conditions that may cause depression and lack of energy.

Diagnosis for Seasonal Affective Disorder
A medical professional is required to appropriately diagnosis Seasonal Affective Disorder

Is There Treatment For SAD?

Treatment for SAD has focused chiefly on winter SAD, but some treatment methods apply to those suffering from summer SAD. Below are a list of some of the most common treatments.

Vitamin D Supplementation To Treat SAD

As many people diagnosed with SAD have low vitamin D levels, doctors may prescribe vitamin D supplementation. It is vital to follow your doctor’s prescription for taking vitamin D, as too much can be as harmful as too little. 

Vitamin D is known as Calciferol and is a fat-soluble vitamin. This means that it should be taken with the consumption of a meal containing fats to maximise the uptake.

Vitamin D is stored in fat in our body and is slowly released as it is needed. 

Vitamin D is important in the production of serotonin. If your serotonin levels are low, it would be wise to have your vitamin D levels assessed by taking blood. The blood is analysed at a laboratory, and the doctor will recommend the correct course of vitamin D supplementation.

Are SSRI Antidepressants Helpful For SAD?

Selective Serotonin Reuptake Inhibitors (SSRI) are medications that increase the availability of serotonin in the body. There are numerous SSRI medicines, and your doctor will assist you in prescribing the best one for you. 

Some critical factors to note in the use of SSRI’s are:

  1. It may take some time to find the SSRI best suited to your body. If one is not working, return to your doctor and try another.
  2. SSRIs take a minimum of two weeks to begin showing an effect on mood, and this can extend to up to four weeks.
  3. SSRIs should be taken for at least three to six months to prevent relapse.
  4. SSRIs may cause side effects which you find difficult to live with. Contact your doctor to discuss the medication.
  5. Do not stop taking SSRIs suddenly unless your doctor instructs you to do so. 

What Is Bupropion And Can It Help SAD?

Bupropion is usually known by its trade name Wellbutrin. It is a medication that increases dopamine in the body. Dopamine is the pleasure and calming neurotransmitter that our body naturally produces. Some people cannot tolerate SSRIs and do better with Wellbutrin.

An advantage of Wellbutrin is that it boosts energy levels and can aid concentration which are problems experienced by SAD sufferers.

Light Therapy for Seasonal Depression

Light therapy is founded on the idea that the shortened daylight hours in winter are responsible for triggering or causing SAD.  Light therapy combats this by exposing individuals struggling with SAD to artificial lights for set periods. 

Light Therapy for Seasonal Depression
Light Therapy (SAD Lamps) are one possible treatment for Seasonal Affective Disorder

This therapy is sometimes called phototherapy or Bright Light Therapy (BLT). The best results have been obtained when the light exposure occurs in the morning, before or up until noon.  

Although light therapy may seem innocuous, it is recommended that it be closely monitored by a health professional as there can be side effects. The side effects are rare, but anyone who is suicidal must be closely monitored. These include:

  1. Irritability
  2. Headache
  3. Eye strain or damage
  4. Insomnia
  5. Suicidal thoughts have been noted occasionally in the first few days of therapy.

Some medications cannot be used in conjunction with light therapy. They increase the sensitivity to light and cause unwanted and problematic issues. Check with your doctor before beginning light treatment.

What Are SAD Lamps?

SAD lamps are used in light therapy for people that struggle with SAD. These lights are UV free and need to generate approximately 10 000 lux of cool-white fluorescent light ideally. Lux is measured by multiplying the area of the light source by the light intensity. 

It is critical to reduce glare on the eyes, so the light source should have a glare-free feature or should be on a swivel hinge so that you can tilt the light away from your eyes. 

The SAD lamp should be a minimum of 12 – 15 inches to get maximum benefit. Small lamps can be difficult to use as you must remain close to them, and you may need to increase the frequency of use. 

SAD lamps are also called lightboxes, and they come in different options. You can choose a SAD lamp which matches your home décor.

How Often Should I Use A SAD Lamp?

Generally, SAD lamps are best used in the morning. Most medical practitioners recommend using the light soon after waking up for 20 – 30 minutes. This can be repeated later in the morning if you need an extended period of light therapy. Follow your doctor’s instructions on the treatment length and duration.

You should position the light 16 – 24 inches (41 -61 cm) away from your face, with the light tilted so that it does not shine directly into your eyes. It is vital to keep your eyes open so that light can enter your retina.

What Are Sunrise Alarm Clocks?

Sunrise alarm clocks are another form of light therapy. These clocks have lights that mimic the fading light of a sunset as you go to sleep or the increasing light of the rising sun. Many sunrise alarms come with adjustable light colour and intensity. 

They function by helping to regulate your circadian rhythm and your body’s production of melatonin. SAD sufferers can go to sleep and wake more naturally. People challenged by SAD with hypersomnia can wake without experiencing the hang-over effect of their bodies erroneously feeling they have had too little sleep. 

Cognitive Behavioural Therapy 

Cognitive behavioural therapy (CBT) is a good alternative for people who cannot tolerate medications or light therapy. Some people opt to use CBT as they feel they can learn a strategy for dealing with depression, and they do not have to keep going back annually. 

CBT can be used in conjunction with light therapy and medication. 

Cognitive behavioural therapy is a method of psychotherapy that focuses on changing thought patterns to influence mood and behaviour. CBT is becoming one of the most popular and effective forms of psychotherapy for many conditions.

Self-Help Tips For Overcoming SAD

There are several habits you can apply to help you deal with SAD. These suggestions are helpful even if you are on medication or using alternative methods to address your depression.

  1. Do not isolate yourself. Keeping in contact with others is vital. Even if you are reading a book, it is beneficial to do this in the same room as someone else. 
  2. Go to social gatherings when you can. Being around people can help to give you energy and take your focus off your problems. 
  3. Sit out in the sunlight every day. The best time is around noon as it has been shown that this is the most beneficial light for elevating mood. It will also help restore vitamin D levels.
  4. Eat healthy meals and maintain a regular dietary regime to ensure you are getting enough nutrients, vitamins and minerals.
  5. Exercise will help to boost your mood naturally. If you do not have the energy to overcome your SAD inertia, arrange with a friend to collect you or meet you for exercise. Give the friend permission to be forceful when insisting you accompany them to do exercise.
  6. Concentrate on good sleep hygiene by keeping the same bedtime each night and getting up at the same time. Avoid binge watching television or staying up too late. Nights are often the times you will feel worse, and it increases the difficulty of getting up in the mornings.  
  7. Take your prescribed medication regularly. Do not stop as soon as you feel better.
  8. Practice breathing exercises and mindfulness to help break you out of a negative thought cycle.
  9. Request help if you are not coping. If you feel unable to summon the energy to find medical help, ask a friend or family member to assist you.
  10. Spend time with a pet. Studies have shown that pets can improve mood, reduce stress and anxiety and even decrease high blood pressure.
  11. Join a group that assists other people or animals. Focusing outwards will help you feel better as it takes your mind off your stress and depression. If you think it is too difficult to have the energy to start this, ask a friend to join you and help you become involved. 
  12. Try to spend time outdoors in nature. Green therapy or ecotherapy has been shown to be immensely successful in overcoming mental health issues. 

Frequently Asked Questions About SAD

In this section, we will address questions that are commonly asked about SAD. If you have any further questions, contact a healthcare provider, mental health worker or counsellor.

SAD is a seasonal depression that usually occurs in winter. It is diagnosed by health care professionals, and there are many effective forms of therapy to assist sufferers. Contact a medical professional, support group or family member to ask for help.