Seasonal affective disorder

Seasonal affective disorder Definition

Seasonal affective disorder (SAD) is a mood disorder experienced by many individuals in the winter months. People suffering this condition experience “blues” or a season depression that is characterized by a desire for starchier foods, withdrawal or oversleeping.

The disease is also referred to by various other names, such as:

  • Winter depression
  • Summer blues
  • Winter blues
  • Seasonal depression
  • Summer depression

Seasonal affective disorder ICD10 Code

The ICD10 Code for this disorder is F33.

Seasonal affective disorder Incidence

The prevalence of this disease in the U.S ranges from as low as 1.4% in Florida to as high as 9.7% in New Hampshire. It is supposed to be more common than was thought initially.

Seasonal affective disorder History

The condition was described formally and named as “Seasonal affective disorder” by Norman E. Rosentha; and his co-workers at the National Institute of Mental Health in 1984. The condition has been studied only since the 1980s although “winter blues” have been recognized for long.

Seasonal affective disorder Symptoms

This form of depression arises at the same time every year. The majority of SAD sufferers start experiencing the symptoms in the autumn which may continue into the winter season. Patients typically feel moody and it seems to them as if all energy has been sucked out of them.

In rare cases, SAD results in depression in the early summer months or in the spring season. In such cases, the problems begin in summer or spring and continue till winter. In either case, the problems may appear mild and gradually become more and more severe as the season progresses

SAD symptoms in winter

The signs of the winter-onset form of this condition include:

  • Hopelessness
  • Depression
  • Anxiety
  • Loss of energy
  • Oversleeping
  • Weight gain
  • Difficulty in concentrating
  • Social withdrawal
  • Loss of interest in activities once enjoyed
  • Sensation of heaviness in the arms or legs
  • Changes in appetite, particularly a craving for carbohydrate-rich foods

SAD symptoms in summer

The symptoms of the summer-onset form of this condition are:

  • Anxiety
  • Sleeping difficulties (insomnia)
  • Agitation
  • Irritability
  • Poor appetite
  • Weight loss
  • Increased sex drive

Reverse Seasonal affective disorder

In some people affected with Bipolar disorder, the summer and spring months can give rise to the signs of mania or hypomania (a less severe type of mania). This is referred to as Reverse Seasonal affective disorder. Its signs typically include:

  • Agitation
  • Hyperactivity
  • Persistently elevated mood
  • Rapid thoughts and speech
  • Unbridled enthusiasm that are exaggerated with regard to a particular situation

Seasonal affective disorder Causes

The exact cause of this disorder is still unknown. It is possible however, that the development of the condition is influenced by various factors like:

  • Age of patients
  • Genetics
  • Presence or absence of mental health conditions
  • Natural chemical makeup of the body

Some specific factors, that may come to play a role in the occurrence of this disease, include:

Serotonin levels

A reduction in the level of serotonin, a chemical in the brain (neurotransmitter) that affects the mood, may play an important role in the development of this disease. Low amounts of sunlight also cause a reduction in serotonin and trigger symptoms of depression. It is due to this reason that people living in areas far from the equator and enjoying only low amounts of sunlight are often found to develop this condition.

Circadian rhythm

It is also known as the biological clock of the body. Reduced level of sunlight in the autumn and winter months may disrupt the internal clock of the body that usually instinctively makes people aware when to sleep and when to stay awake. The disruption of this biological clock may give rise to feelings of depression.

Melatonin levels

A change in season can cause disruption in the balance of Melatonin, a natural hormone, which plays a role in regulating the mood and sleep patterns.

Seasonal affective disorder Diagnosis

The diagnosis of this disorder requires doctors or mental health care providers to conduct a thorough evaluation of sufferers. This usually involves:

Physical examination

A physical check-up may be conducted to detect any underlying health problems that can be related to depression.

Asking detailed questions

Patients are likely to be asked about their symptoms, such as mood as well as seasonal changes in their behavior and thought patterns. They may also be questioned about their eating and sleep patterns, jobs, relationships or other aspects of their lives. In some cases, patients may be handed over a questionnaire that they have to fill. This saves time on the part of both doctors and patients and lets the former assess the psychological status of the latter more easily.

Medical exams

There are no specific medical tests for the diagnosis of SAD. However, patients may be asked to go through blood tests and other exams to rule out the presence of underlying disorders if physicians suspect a disease to be the cause or worsening factor for the disease.

Seasonal affective disorder Diagnostic Criteria

Patients must meet certain criteria, spelled out in the DSM (Diagnostic and Statistical Manual of Mental Disorders), to be diagnosed with SAD. The manual has been released by the American Psychiatric Association. It is used by mental care providers to detect mental disorders and insurance firms to reimburse for medical treatment.

The diagnostic criteria for the disorder include:

  • Patients must experience depression and other signs for a minimum period of two consecutive years, during the same season each year
  • The period of depression must follow periods without depression
  • There are no possible explanations for the alterations in the mood or behavior of sufferers

Seasonal affective disorder Differential Diagnosis

SAD is regarded as a subtype of Bipolar disorder or depression. Even after a complete assessment, a physician or mental healthcare provider may find it difficult to distinguish this disease from other forms of depression or mental health disorders due to the similarity of symptoms. Due to this reason, physicians should take adequate steps to ensure as far as possible that patients are actually suffering from SAD and not some other mental disorders.

Seasonal affective disorder Treatment

The treatment of this disease may include:

Light therapy

In this process, also known as Phototherapy, patients have to sit a few feet away from a specialized box to be exposed to bright light. This light resembles outdoor environment and seems to produce changes in the neurotransmitters that are associated to mood.

This is one of the first line of curative procedures for SAD. The technique usually begins working in 2-4 days and leads to few side effects. Although research is limited regarding this type of cure, it seems to be the most effective for the majority of SAD sufferers and in alleviating their symptoms.


Some SAD patients find benefit from treatment with antidepressants, particularly in cases where the symptoms are of an acute nature. The antidepressants that are commonly used for SAD include venlafaxine (Effexor), paroxetine (Paxil), fluoxetine (Prozac, Sarafem) and sertraline (Zoloft). In individuals with a history of SAD, Wellbutrin XL – an extended-release version of the antidepressant Bupropion may help prevent episodes of depression.

Doctors may recommend initiating treatment with an antidepressant before the symptoms typically arise every year. Patients may also be suggested to continue taking the medicine beyond the time the symptoms usually go away.


It is another effective curative option for SAD. It can help patients identify and alter negative behaviors and thoughts that may make them feel worse. They can also be taught healthy ways to cope with the condition and manage stress.

Seasonal affective disorder Complications

The symptoms of SAD should be taken seriously. The problems associated with this disorder, as is common with other forms of depression, can take a turn worse and give rise to various complications if left untreated. These may include:

  • Social withdrawal
  • Substance abuse
  • Suicidal thoughts or behavior
  • Problems in school or workplace

Treatment can be effective in helping patients avoid complications, particularly in case SAD is detected and cured before its symptoms take a turn for the worse.

Seasonal affective disorder Prognosis

The outcome of the disease is generally good with proper treatment. However, certain SAD sufferers are found to have the condition for as long as they live.

Seasonal affective disorder Risk Factors

The possible risk factors for this disorder include:

Family history

The condition may have a genetic association and SAD sufferers may be more likely to have blood relatives affected with the disease, as is true in other forms of depression.

Being female

SAD is detected more in women than in men although its symptoms are more acute in men.

Having other depressive conditions

An individual may suffer from worsening of depression in case he or she suffers from either Bipolar disorder or clinical depression.

Residing far from the equator

SAD seems to be more common in individuals who live in regions far north or south of the equator. This may be due to longer days during summer or reduced sunlight during winter.

Seasonal affective disorder Prevention

Doctors are yet in the dark regarding ways to prevent this condition. However, patients may be able to prevent the symptoms from getting worse progressively by taking steps in the early stages of the condition to manage its symptoms. Some individuals find benefit in starting treatment before the symptoms of SAD begin in the autumn or winter and continuing cure past the time when the symptoms usually go away.

If patients are able to control the symptoms before they get worse, it may be possible for them to avoid severe changes in the appetite, mood and energy levels.


There are days when even the most normal individuals feel down and depressed. However, it is time to see a doctor if you are feeling the “blues” for most days and cannot seem to get motivated even for the activities that you usually enjoy. This is especially important if you find your appetite and sleep patterns have changed or you are feeling hopeless, suicidal and increasingly dependent on alcohol and other similar additive substances for joy and comfort.


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