Few behavioural disorders are static in nature; instead, many are episodic, exhibiting periods of severe symptoms and periods of mild symptoms. One of the most well-known causes of behavioural fluctuations (even in the absence of another known disorder) is the changing of the seasons. Indeed, over the last two decades, the term “Seasonal Affective Disorder” or SAD has been used to address the prevalence of behavioural changes that occur in tandem with seasonal patterns. SAD is generally most pronounced during the dark winter months.
However, there is one seasonal behavioural correlation that has not yet been studied in adequate depth: The possible link between ADHD symptom severity and SAD. While a diagnosis of ADHD requires a symptomatic period of at least 6 months, it is entirely possible that these symptoms may follow a pattern of seasonal fluctuation. Understanding this pattern, if indeed it exists, could both provide more insight into the disorder itself (ADHD) and help clinicians avoid accidentally over-medicating patients diagnosed during a “high symptom” period.
ADHD And SAD: What We Know
While the link between ADHD and SAD is not definitively established at present, several relevant studies have been conducted, shedding some light on a possible connection. Their results are as follows:
- Those with ADHD are more likely to experience SAD than members of the general population, according to a study conducted by Dr. Robert Levitan from the University of Toronto. (The symptoms of SAD include depression, lethargy, and poor concentration, among others.) As expected, those at higher latitudes experienced this correlation more profoundly than those closer to the equator. This study also revealed that, just as women are more prone to SAD in general, women with ADHD are more vulnerable to SAD than men with ADHD.
In addition to these expected results, the study yielded some unique and interesting data. Most notably, it was discovered that those with the inattentive subtype of ADHD (rather than the hyperactive/impulsive or blended subtypes of the disorder) were most prone to seasonal affective issues. This finding builds on the existing theory that comorbid depression is experienced by those with inattentive ADHD more often than other types.
- ADHD and SAD both respond well to the use of “pseudo-stimulant” anti-depressants like buproprion (Wellbutrin). While this does not, of course, prove a link between SAD and ADHD (as Wellbutrin is useful for treating a wide spectrum of different disorders), most experts feel that this fact is still worth noting. Wellbutrin is still used frequently as an ADHD treatment (in place of true stimulant medications) in the event that a patient has both ADHD and a depressive disorder. This may make it useful for also treating ADHD/SAD patients who do not have comorbid (year-long) depression.
- Those with ADHD experience greater seasonal disturbances in their circadian rhythms. Not only do those with ADHD often experience atypical circadian rhythms in general (staying up far later or waking up far earlier than the general population), emerging data suggests they may also be more prone to seasonal fluctuations in their sleeping habits. That is, they may sleep much more or much less during the winter months and their sleeping hours may become increasingly deregulated.
There is, however, hope for those with ADHD who are experiencing both SAD and circadian rhythm disturbances: There is a great deal of evidence to suggest that light therapy, when administered at the correct wavelengths, can treat both the depressive and inattentive symptoms of SAD and help to regulate the patient’s internal clock. (Note, however, that in rare instances the stimulant medications used to treat ADHD can interact negatively with light therapy as they can produce light sensitivity as a side-effect.)
- Omega 3 (n-3) fatty acid deficiency may play a role in all of the above-mentioned issues: SAD, ADHD, and circadian rhythm disturbance. While no single cause for ADHD or SAD has ever been identified, multiple studies have shown that Omega 3 deficiency—which is prominent among people with both SAD and ADHD—may play a role in exacerbating these conditions. Likewise, new research has revealed a surprising correlation between Omega 3 deficiency and circadian rhythm disturbance. It is believed that Omega 3 fatty acids may be involved in the production of the sleep hormone melatonin; as such, a lack of it could lead to a poorly-regulated sleep-wake cycle. Because sleep deprivation (and poor sleep quality) frequently leads to mood disturbances and problems with concentration and short-term memory, Omega 3 deficiency could be having a multifaceted impact on both ADHD and SAD.
The above theory is bolstered by the fact that seasonal affective disorder is quite uncommon in Iceland, despite the nation’s extreme northerly latitude. The Icelandic people eat a diet that is very rich in cold-water ocean-going fish, one of the world’s best sources of Omega 3 fatty acids. As such, a dietary change and/or Omega 3 supplementation could provide a relatively simple, easy, and side-effect-free way to treat ADHD, SAD, and circadian rhythm disturbance (particularly if used in conjunction with light therapy and vitamin D supplementation).
While the link between SAD and ADHD is intriguing and potentially important, it’s essential to keep in mind that ADHD has already been more strongly linked to many other potential comorbid issues (in addition to other learning disabilities, ADHD is associated with a higher risk of Tourette's, anxiety, conduct disorders, and depressive disorders). Before assessing how much the fluctuation of the seasons is affecting a patient with ADHD, mental health professionals should therefore rule out these other, more firmly linked conditions first.
Image Source: Pixabay.com
