Late spring and summer, as time frees children from airless school-rooms, and pale white arms peek out from under the season’s first short-sleeved shirts, has historically caused problems for people with bipolar disorder. For well over a century researchers and doctors alike have affirmed and re-affirmed that hospitalizations for manic episodes peak in the summer months.
In fact, as far back as the days of the ancient Greeks, Aretaeus in the 2nd century A.D. recognized the connection between mania and late-summer/early-autumn, and saw this time as setting into motion the episodes that would, untreated, wreak havoc in spring.
So parts of his theory ran:
Adult men, therefore, are subject to mania and melancholy, or persons of less age than adults. Women are worse affected with mania than men. As to age, towards manhood, and those actually in the prime of life. The seasons of summer and of autumn engender , and spring brings it to a crisis. . . . Mania is something hot and dry in cause, and tumultuous in its acts. [emphasis mine]
His correlation was lost with the ravages of time.
However, bipolar disorder scholars Edwin Fuller Torrey and Michael B. Knable note that as far back as the early 19th century, a pair of French physicians noticed that between 1806-1814 the number of admissions to a Paris mental hospital were up 20% more in the summer months than in the winter months. They didn’t delve into cause, but looking back, we can guess what was boosting hospital enrollment.
Thus the data on increased hospitalizations and the theory that mania correlates with season both been around for quite some time–but it took decades to begin to determine scientifically–again and again–that the theory and the data consistently go hand in hand.
And it is interesting how many times admissions data were looked into–depending upon the angle of the sun in the area, distance from the equator, the location of hemisphere–and one, it seems, was run because a continent got left out. But the consistency of the findings become a drum-beat, warning anyone with bipolar to watch any mood lability carefully, so that the rising sap of spring doesn’t have a correlate in mood.
The French statistics were re-noted by an English study of all psychiatric admissions from 1970-1973 in England and Wales. It found manic admissions peaked in July–and hit a minimum in January. Thus the connection of mania with summer was firmly taking root in the psychiatric mind, reinforced by subsequent research (Symonds & Williams 1976, Walter 1977, Myers & Davies 1978, Hare & Walter 1978 are only some examples).
But questions needed to be answered.
What was causing such a connection? Was it something inherent in the European summer?
And if so, would this apply in the southern hemisphere, then?
Or was the mania in response to temperature and light increases–or perhaps even humidity? Would the correlation apply in places with very little seasonable variation?
Exactly how over-arching is this connection?
Well, the statistics hold true even in the southern hemisphere, with its reversed seasons. In the 1991 paper, “Mania and seasonality in the Southern Hemisphere,” the authors studied psychiatric admissions for mania over the course of 9 years in New Zealand–and a consistent spring/summer peak (the peak was a month earlier than some of the earlier studies, but the overlap is very real) for mania admissions was found. Mean daily temperature and day lengths were found to be more relevant indicators of admission frequency than hours of bright sunshine or relative humidity.
That would become relevant in studies done in the subtropics, where the hours of daylight and temperatures stay relatively constant.
Two 2006 studies in the subtropics gave the lie to the theory that the connection was temperature- and light- related.
In a Brazilian study, researchers analyzed the charts of 269 manic patients admitted from 1996 to 2000 to a Brazilian psychiatric hospital. The graph says it all:
Here there’s an increase in early spring, it’s true–but the numbers soar again in June, July and August.
Taiwan has even less temperature shift, so the researchers justified their study as one done in ”a subtropical area with fairly constant weather condition.” Some still theorized that it was the changes in weather temperature and light that sparked the manic episodes–and that theory still has explanatory potential, but it wasn’t realized here.
This study used hospitalization data from the Taiwan National Health Insurance Research Database from 1999-2003, covering a total of 64,718 hospital admissions for bipolar disorder involving 14,899 patients.
Although June didn’t find a particular increase in admissions for manic episode, there was a sharp increase in July, with a peak in August (similar to the Brazilian chart, notably).
The researchers conclude that
this study, (along with the report by Kerr-Correa et al. (1998), provides confirmation of the existence of seasonality with regard to mania, even in subtropical areas. . .[with] variations in weather conditions of a much lower magnitude. [emphasis mine]
You might think that would have covered it, but, if so, you’d have failed to notice that some people got left out. Well, I really mean some continents–and I really mean one, since no one seems to have proposed a study of bipolar mania admissions in Antarctica. The numbers are low, don’t worry. But. . .there was Africa.
So just to leave no stone unturned, researchers Mostafa Amr (Mansoura University, Egypt) and Fernando Madalena Volpe (Hospital Foundation of Minas Gerais, Brazil) gave it another go-round, observing that ”studies of seasonal variation in psychiatry are lacking in northern Africa.” True enough.
Egypt has enough trouble these days, without having to feel left out of bipolar research, so, grant approved, the two studied 3346 patients admitted to a university psychiatric hospital in Mansoura between 2003 and 2007.
I bet you’ll never guess what they found.
Well, first, actually, they discovered that schizophrenia, as opposed to the mood disorders, had no seasonal variation, which is a fact worth knowing.
They then determined that admission rates for bipolar or unipolar depression were highest during the winter months, with a peak in December.
And. . . .drum roll please. . . .
admission rates for bipolar mania were highest during the spring and summer months, with a peak in June, and lowest during the winter months, with a trough in December.
I know. It’s a little bet of a let-down. Weren’t you almost kind of hoping they’d have found that there was a mania run on the hospitals in February, just to stimulate some deep thinking?
Not to be.
As we’ve seen, different studies have indicated variable peak times for the psychiatric admissions, with some tending towards later spring, others smack in summer’s center, and some even leaning towards late summer. But they all tend to have overlap around the months of June and July.
So, in short, whether you’re an ancient Greek, or you hail from North Africa, or you’ve spent your days in sub-tropical climates, or you’ve lived in the land down under–or you’re just from around the block in Chicago–when spring rolls in to summer it’s time to make sure you have a heightened awareness to any manic symptoms you might exhibit.
Mood charting will help, or tracking your sleep, or setting up some extra appointments with your psychiatrist.
It’s worth the effort. Summer should be a time of beach novels and dahlias and lazy nights drinking ice tea in the back yard hammock while being devoured by mosquitos.
Don’t let it be a time of a hospital admission that will make you just another statistic in the seasonal mania pattern.
Amr M, Volpe FM. Seasonal influences on admissions for mood disorders and schizophrenia in a teaching psychiatric hospital in Egypt
Journal of Affective Disorders 2012; 137(1):56-60.
Christodoulou GN, Ploumpidis DN, Karavatos A, Eds. Anthology of Greek Psychiatrist Texts. Athens: BETA Medical Publishers, 2011.
Hare EH, Walter SD. Seasonal variation in admissions of psychiatric patients and its relation to seasonal variation in their births. Journal of Epidemiology and Community Health 1978; 32:47-52.
Volpe FM, Del Porto JA. Seasonality of admissions for mania in a psychiatric hospital of Belo Horizonte, Brazil. Journal of Affective Disorders 2006; 94(1-3):243-8.