"It's the weather!" I tell myself as I sleep longer than expected and feel a little blue. Guilty, am I, for regularly blaming the weather on my mood. Despite this, I also wonder just how much the weather can really affect my mood.
A sub-type of depression, seasonal affective depression is a diagnosis given to individuals that display symptoms of depression that occur during seasons - commonly during fall and winter. People with seasonal affective depression - or SAD, a rather appropriate acronym - can often experience symptoms of depression during particular seasons. Common symptoms include: fatigue, increase in appetite, increased amount of time sleeping, feelings of guilt, depressed mood and marked loss of interest in pleasurable activities.
Let's take a step back and just examine research that provides some evidence for this phenomenon of how weather affects mood.
"Hsiang et al. (2013) found a link between human aggression and higher temperatures. As temperatures rose, the researchers noted that intergroup conflicts also tended to jump — by 14 percent (a significant increase). The scientists also found interpersonal violence rose by 4 percent."
"... Marie Connolly (2013) found that women who were interviewed on days “with more rain and higher temperatures [reported] statistically and substantively decreasing life satisfaction, consistent with the affect results.” On days with lower temperatures and no rain, the same subjects reported higher life satisfaction."
"... researchers (Koskinen et al., 2002) found that outdoor workers were far more likely to commit suicide in the spring months than during the winter months. For indoor workers studied, suicides peaked in the summertime."
"A comprehensive meta-analysis performed in 2012 (Christodoulou et al.) on the seasonality of suicide found a universal truth: “Studies from both the Norther and Southern hemisphere report a seasonal pattern for suicides. Thus, it seems that seasonality is observed with an increase in suicides for spring and early summer and an analogous decrease during autumn and winter months, that is a constant, if not a universal behavior that affects both the Norther and Southern hemisphere.”"
"A Swedish study (Makris et al., 2013) that examined all suicides in the country from 1992 to 2003 found a similar spring-summer seasonal pattern peak for suicides as well — especially those treated with an SSRI antidepressant."
"Can Weather Affect Your Mood?"
John M. Grohol, PsyD
Research provides some physiological reasons as to why an estimated 3%-9% of the U.S. population is vulnerable to SAD. Many studies have highlighted how people with SAD see an improvement in symptoms through exposure to bright light. Living away from the equator also means days are shorter and there is less exposure to sunlight. Furthermore, less sunlight can also cause less exposure to vitamin D, and low vitamin D levels have been linked to depression.
Another potential reason for this phenomenon includes a learning theory. In certain cases winter weather can be associated with a memory due to the body's natural physiological response. Winter months can often be associated with a plethora of areas that personally affect us, often negatively (illness, loneliness etc.).
If we do experience more severe symptoms of depression - it is not deterministic and does not mean that we are doomed to spend our winter season in bed. This component is knowledge and the knowledge of why we may possibly feel more depressed allows us to make decisions to help ourselves. Similar to a medical condition with "flare ups" we can think of SAD as being a time where we could be more aware of a "flare up" of depression and take measures to help ourselves. This can mean seeing a therapist, practicing self-care or deciding to go on a small dose of anti-depressants. The golden rule "know thy self" applies, and it applies as a means to know ourselves well enough to expect these seasonal "flare ups" and put forth the effort to minimize the symptoms of depression.