Do You Suffer From Seasonal Depression? Tests You Can Take

Seasonal depression, also known as winter depression and seasonal affective disorder (SAD), is a type of depression that has a seasonal connection. Getting a diagnosis can be tricky, and you might be wondering if there are any tests for SAD. 

Have you considered clinical trials for Seasonal affective disorder (SAD)?

We make it easy for you to participate in a clinical trial for Seasonal affective disorder (SAD), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

What is seasonal affective disorder?

Seasonal affective disorder (SAD) is a subtype of major depression that only affects people during a particular season. It’s often referred to as winter depression because it commonly affects people during the winter. 

However, SAD isn’t limited to the colder months. Although quite rare, some people experience SAD during summer instead. 

People with SAD only experience this condition once a year. When their affected season has passed, their depression disappears and doesn’t come back until the same time the following year. 


The exact cause of SAD remains unknown. However, scientists have linked SAD to an interaction between environmental and biological factors. 

Environmental factors include your location, seasonal changes, and light. Biological factors include your body clock, melatonin, serotonin, and your environment or genes, influencing biological factors. 

People who live in seasonal locations, especially those in the far northern or southern latitudes, are more susceptible to SAD due to the variation in light exposure they experience throughout the year. Light exposure varies because the days are longer during summer and shorter during winter, and the differences become more extreme the farther north or south you live. 

Due to this variation, you might have difficulty adapting to a particular season. As a result, your body clock is disrupted, and chemicals like melatonin and serotonin become imbalanced, affecting your sleep, eating habits, and mood. 

If you have trouble adapting to a particular season, like winter, for example, then you need to assess why this is difficult for you as it may help with your diagnosis. 


A simple indication of whether you might have SAD is to assess your symptoms. As mentioned earlier, it can be helpful to list all of the symptoms you’re experiencing before seeing your doctor. 

Symptoms of winter SAD may include:

  • Depression

  • Feeling of hopelessness

  • Social withdrawal

  • Tiredness

  • Increased appetite 

  • Cravings for carbohydrates or sweet food 

  • Weight gain

  • Delayed onset of sleep 

  • Hypersomnia - oversleeping and daytime tiredness

Symptoms of summer SAD, on the other hand, may include: 

  • Depression

  • Agitation 

  • Irritability 

  • Low mood

  • Tiredness

  • Decreased appetite

  • Insomnia - difficulty falling asleep and staying asleep

While many of these symptoms crossover with other types of depression, you need to consider the duration and time your symptoms started. Doing so will better indicate whether you have seasonal depression or a different kind of depression. 

If you have winter SAD, you’ll notice that your depression starts around late fall or early winter. You might be able to link this to when the days become shorter or when the clocks are turned back for daylight savings. 

You’ll also notice that these symptoms persist until late winter or early spring. Then the depression subsides until the next autumn or winter when symptoms begin again. 

Your depression starts around late spring or early summer if you have summer SAD. You might be able to link this to when the days grow longer or when the clock is set forward for daylight savings. 

Your symptoms last until late summer or early fall. Then the symptoms go away until the next spring or summer when they return. 

While listing your symptoms is helpful, it’s also useful to record when your symptoms start and how long they persist. 

You could also monitor your weight. For example, if you have winter SAD, you might notice that you put on weight during winter due to an increased appetite and cravings for sugars and carbohydrates. Or, if you have summer SAD, you might lose weight if your appetite decreases. 

You may also need to take note of your symptoms for at least two years. A yearly pattern of symptoms needs to be present to diagnose someone with SAD. 

If you have only experienced SAD once, it might be difficult for your doctor to determine whether it genuinely is SAD or if you have another type of depression.

Keeping a record of your symptoms will give your doctor a clearer picture of what’s happening and how your symptoms impact your life.

Who is susceptible to developing the seasonal affective disorder?

Anyone can be affected by SAD. However, researchers¹ have determined that some people have a higher chance of developing SAD than others.

Where you live has a significant influence on whether and to what degree you develop the seasonal affective disorder. People who live in seasonal climates north or south of the equator are more susceptible than those in tropical areas. In addition, people who live further north or south are most at risk.

Furthermore, women are more likely to develop SAD than men, and the two age groups most affected by SAD are young adults and older adults.

If you have a history of mild depression, you are more susceptible.

Finally, if you live a sedentary lifestyle with little exercise, you also might be at greater risk of developing SAD.

What tests can you take to diagnose seasonal depression?

Before your diagnosis

Physical tests exist, which you can take to determine whether you have SAD. If you want a diagnosis, your doctor needs to assess your symptoms and situation.

Since some symptoms of SAD cross over with other health conditions, your doctor might order tests, such as bloodwork for these conditions, if needed.

Your doctor might diagnose you with depression or SAD if they can find no other possible explanation.

Before the appointment with your doctor, it might help to write a list of every symptom you are experiencing and when you begin to feel them. Doing so will help your doctor assess you for SAD or determine whether you have another health condition.

If your doctor suspects you have depression, they need to determine which type of depression you have. From here, they’ll ask you a series of questions about your symptoms and wellbeing.

Being prepared before your appointment can help with your diagnosis. You can do this by understanding the symptoms and causes of SAD to assess which aspects apply to you.

During your diagnosis

If your doctor suspects that you have SAD, they’ll ask you a series of questions. Some of these questions might be based on the criteria set by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

The DSM-5 is a tool used by healthcare professionals for diagnosing mental disorders like depression and SAD.

Since many disorders outlined in the DSM-5 cannot be determined through physical testing, this manual instead provides criteria so doctors can base their decisions on a series of inclusions and exclusions of symptoms.

The criteria for SAD set by the DSM-5 include:

  1. There needs to be a clear pattern or link between depressive episodes and a particular season. 

  2. To determine a clear pattern, there needs to be a history of SAD for at least 2 years. 

  3. There needs to be remission from depression outside of the affected season. 

  4. Should depressive episodes occur outside of the affected season, these episodes must occur less frequently than the seasonal episodes. 

If you’re worried that you may not fit these criteria fully, keep in mind that the DSM-5 is used as a guide only.

For example, you may have only experienced SAD for one year instead of two. In that case, your doctor will ask you to follow up on this a year later while still treating your current symptoms in the meantime.

In addition, your doctor will ask you questions about your symptoms and your situation. Your doctor may also use another questionnaire, such as the Seasonal Pattern Assessment Questionnaire (SPAQ), to assess whether you have SAD.

The SPAQ includes questions relating to six aspects of SAD, and a score is derived from each set of questions. These questions relate to:

  1. Sleep

  2. Mood

  3. Energy 

  4. Appetite

  5. Weight

  6. Socialization

Like the DSM-5, these questions are used as a guide, and your doctor will consider other aspects of your situation before providing a full diagnosis.

Overall, no physical tests are available for diagnosing SAD. The DSM-5 and the SPAQ are just two examples of criteria- or questionnaire-based methods that your doctor might use.

When to see a doctor

If you’re experiencing a low mood or any of the symptoms listed for SAD, you shouldn’t hesitate to book an appointment with your doctor. A doctor can provide you with a proper diagnosis and treatment for SAD if necessary.

If you’re unsure whether you have SAD, you should still seek medical advice for clarification.

Should your symptoms of depression worsen before or after your diagnosis, go to a doctor immediately.

The lowdown

Getting your SAD diagnosed properly is important so that your doctor can find a treatment plan that’s suitable for you. While no physical tests can be used to diagnose SAD, other tools, such as the DSM-5 or the SPAQ, can be used by your doctor instead.

Regardless of what causes your depression, you should not hesitate to discuss your concerns with a doctor.

Have you considered clinical trials for Seasonal affective disorder (SAD)?

We make it easy for you to participate in a clinical trial for Seasonal affective disorder (SAD), and get access to the latest treatments not yet widely available - and be a part of finding a cure.

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