Thanks for your interesting question! I believe I've found the study
A recent study by Dr. Aric Sigman revealed that more and more people
in Western society suffer from "product claustrophia" when faced with
choosing between dozens of brands of the same product.
Sigman released his findings in a report titled "The Explosion of
Choice: Tyranny or Freedom." In a June 2004 article in the London
Daily Mirror, Sigman is quoted as saying "Humans now have to make more
decisions in a single day than a caveman did in a lifetime?I've
travelled to countries such as Iran and Burma, where people have
limited personal choice, and from Tonga to Timbuktu where there's
limited consumer choice.
"I wanted to see whether Western assumptions regarding greater choice
bringing greater happiness was true. They aren't.
"Choice is beneficial up to a point. But limitations, restrictions and
boundaries can have a strangely liberating effect."
< http://www.productoftheyear.co.uk/default.asp?subpage=474§ion=290 >
Sigman's study was commissioned to coincide with the Product of the
Year initiative, in which 20 000 consumers will judge products based
on innovation and adherence to "new and improved" claims.
Similar claims have been posited by US academic Barry Schwartz, author
of "The Paradox of Choice: Why more is less." In an article in UK
publication The Guardian titled "Electing for non-selection," Patrick
Butler sums up Schwartz's research and findings as follows:
"[Schwartz] has examined US supermarkets, pension plans, and
healthcare, and discovered that people often respond to superabundant
choice by making no choices at all - even when doing so runs counter
to their own interests. Schwartz also links the explosion of choice to
the rise in clinical depression in developed countries. People feel
they've no time to choose "properly"; they fear they'll make the
"wrong" choice; and their expectations become absurdly inflated. The
net result, he says, is unhappiness."
< http://society.guardian.co.uk/societyguardian/story/0,7843,1181048,00.html >
Bryan Appleyard of New Statesman makes these observations in a review
of "The Paradox of Choice":
"Schwartz's central point is unarguable--an excess of choice makes us
unhappy and we would be wise to limit the number and range of choices
we have to make. As he acknowledges, however, the modern world is
designed to draw us into the desert of infinite choice. Americans
encounter 3,000 advertisements a day?Wealth and its inevitable
accompaniment, more choice, are not making people happier. Misery is
on the increase. Certainly, very poor countries are more unhappy than
rich ones, but once they pass the subsistence level, happiness does
not grow. And beyond a certain point, it begins to decrease
significantly. "The American 'happiness quotient'," observes Schwartz,
"has been going gently downhill for more than a generation."
< http://www.findarticles.com/p/articles/mi_m0FQP/is_4691_133/ai_n6110497 >
Here are several resources you may find interesting:
Consumers have 'too many choices'
BBC News UK
< http://news.bbc.co.uk/1/hi/uk/724080.stm >
In Weird Math of Choices, 6 Choices Can Beat 600
< http://www.columbia.edu/~ss957/nytimes.html >
Paradox of choice: Why More is Less on Amazon.com
Too Many Choices - Nine Kinds of Kleenex Tissue, Eggo Waffles in 16 Flavors
Wall St. Journal
< http://www.columbia.edu/~ss957/TooManyChoices.htm >
I used the following search strings to find your answer:
grocery store choice anxiety
"explosion of choice"
overwhelmed grocery store choices depression
supermarket choice incidence depression
I hope that my answer has met your needs, and please feel free to
request clarification as needed. All the best!