Mental Health Blog

Diagnosing Seasonal Affective Disorder


“Seasonal Affective Disorder (SAD) is more than just the winter blues,” explains Maureen Montgomery, MD, a pediatrician based in Buffalo, NY. “It’s a subtype of clinical depression that has very specific characteristics.” 

As the name suggests, SAD is a seasonal and cyclical type of depression. In most cases, SAD occurs during the fall and winter months (in the northern hemisphere) when there are fewer daylight hours and less sunlight. Symptoms fully remit at other times of the year (spring and summer).

Here, Dr. Montgomery walks us through key steps in diagnosing and treating SAD.


Confirm a diagnosis of clinical depression

“SAD is a type of depression, so patients must first meet criteria to be diagnosed with  depression,” shares Dr. Montgomery. 

As always, clinicians should keep an eye out for patients who present with symptoms of depression, such as feeling sad or hopeless, impairment in the activities of daily living, changes in mood or behavior, or changes in appetite (over- or under-eating). For the initial diagnosis of depression, clinicians can follow the guidelines taught in REACH’s foundational Patient-Centered Mental Health in Pediatric Primary Care (PPP) course. 

Once a patient has met the diagnostic criteria for depression, it’s then time to assess key factors that could point to Seasonal Affective Disorder


SAD diagnostic criteria and risk factors

“When diagnosing SAD, you are looking for a pattern,” explains Dr. Montgomery. “A SAD diagnosis cannot be made until a clinician can confirm that the patient has experienced seasonal depression for at least two (mostly consecutive) years.” 

With SAD, symptoms of depression will generally begin in fall and winter. The depression will then resolve in the spring and summer. Clinicians should ask patients about the timing of depressive symptoms – when they start and end – and whether this has happened in prior years. 

Clinicians can also consider: 

  • Geography: SAD is more common among those living at northern latitudes. For example, you are likely to see more cases in Alaska or Maine than in Florida. 
  • Family history: Have any family members been diagnosed with SAD previously? 
  • Patient age: Current research shows that SAD is more prevalent among adolescents than children, and is most common in older adolescents and young adults
  • Patient gender: Across age ranges, females are more likely to experience SAD than males. 


Treatments for Seasonal Affective Disorder

As with all mental health disorders, SAD may present with different severity among patients. 

For mild cases, clinicians can coach patients through simple changes to their daily activities and habits that may help. Often called “behavioral activation,” things like getting adequate sleep, healthy eating, getting outside for regular walks/exercise, reducing time on social media, and staying connected to friends and family are all ways to improve mood. Dr. Montgomery shares that, since SAD is more common among adolescents, it’s essential to help them understand that the illness is not their fault, but that they do need to be part of the solution.

If a patient is struggling more, clinicians will want to step up therapy. In addition to traditional treatments for depression, such as cognitive behavioral therapy (CBT), SAD responds well to light therapy. Dr. Montgomery also recommends considering vitamin D supplementation. 

For patients who are experiencing the most severe symptoms of SAD, medications are a mainstay of treatment, together with the therapies mentioned above. As in other types of major depression, SSRIs are the first-line medications for pediatric SAD. In older adolescents and adults, bupropion has been used and there is some evidence that it may prevent recurrence. 

Overall, especially for clinicians at northern latitudes, adding SAD to your differential diagnosis toolbox can be helpful. Explains Dr. Montgomery, “The winter blues happen to many of us. We still do what we need to do, but may pull back a little from nonessential activities. However, when symptoms are clearly impairing function and quality of life, treatment is indicated.”



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