Study: Media misconstrues blues as 'chemical imbalance'
Mar 07,2008 00:00 by Bend_Weekly_News_Sources

A popular, an­ciently rooted idea about clin­i­cal de­pres­sion—that it re­sults from a chem­i­cal im­bal­ance—still finds its way in­to many news re­ports, a study has found.

There’s just one prob­lem: the claim has lit­tle or no ba­sis, the stu­dy’s au­thors say. In fact, the main­stream sci­en­tif­ic view is that de­pres­sion’s causes are simply un­known.

Absinthe Drinker by Pablo Picasso (1901).

The study is tak­ing on added rel­e­vance in light of oth­er new re­search cast­ing doubt on the ef­fi­ca­cy of pop­u­lar an­ti-de­pres­sion med­ica­t­ions. Phar­ma­ceu­ti­cal com­pa­nies some­times ad­ver­tised those drugs as cor­rect­ing a chem­i­cal im­bal­ance.

In the new stu­dy, re­search­ers con­tacted jour­nal­ists who had writ­ten ar­ti­cles about de­pres­sion be­ing caused by a chem­i­cal im­bal­ance—or, as a mod­ern ver­sion of the the­o­ry holds, by lack of a sub­stance called ser­o­to­nin. 

But asked where they had found that in­forma­t­ion, re­porters could­n’t pro­vide sci­en­tif­ic ev­i­dence for the claim, ac­cord­ing to the in­ves­ti­ga­tors. 

The re­search­ers, with Flor­i­da State Uni­ver­s­ity and Lin­coln Me­mo­ri­al Uni­ver­s­ity in Ten­nes­see, said they spent about a year in late 2006 and 2007 mon­i­tor­ing daily news for ar­ti­cles that in­clud­ed such state­ments, and con­tact­ing the au­thors. The find­ings are pub­lished in the re­search jour­nal So­ci­e­ty.

The con­cept of de­pres­sion as a chem­i­cal im­bal­ance is trace­able to the an­cient Greeks, who be­lieved health and ill­ness arise from correct or in­cor­rect pro­por­tions of four sub­stances known as hu­mors.

The no­tion found an ech­o in the more mod­ern hy­poth­e­sis de­vel­oped in the 1960s, that lack of ser­o­to­nin in the brain causes de­pres­sion. But this, too, re­mains un­prov­en, ac­cord­ing to the re­search­ers: its main sup­port, in fact, came from the claimed ef­fi­ca­cy against de­pres­sion of drugs meant to cor­rect this im­bal­ance. 

But re­cent re­search found the drugs, known as Se­lec­tive Ser­o­to­nin Re­up­take In­hi­bi­tors or SSRIs, were less ef­fec­tive than pre­viously be­lieved.

“The me­di­a’s pre­s­enta­t­ion of the the­o­ry as fact is trou­blesome,” said Jef­frey R. La­casse of Flor­i­da State, one of the re­search­ers. In real­ity, “there are few sci­en­tists who will rise to [the the­o­ry’s] de­fense, and some prom­i­nent psy­chi­a­trists pub­licly ac­knowl­edge that [it] is more met­a­phor than fact.” 

The real cause of de­pres­sion is un­known, said Le­o and La­casse, a con­clu­sion al­so ech­oed in stand­ard med­ical texts such as The Di­ag­nos­tic and Sta­tis­ti­cal Man­u­al of Men­tal Dis­or­ders—used by most psy­chi­a­trists—and The Merck Man­u­al of Di­ag­no­sis and Ther­apy.

A re­view of clin­i­cal tri­als pub­lished in the jour­nal PLoS-Medicine last month con­clud­ed that much of the per­ceived ef­fi­ca­cy of the more com­mon SS­RIs was due to the pla­ce­bo ef­fect, in which peo­ple feel bet­ter simply be­cause they know they’re be­ing treated. 

Oth­er stud­ies in­di­cate that for eve­ry 10 peo­ple tak­ing an SSRI, only one or two really ben­e­fit from it, ac­cord­ing to La­casse and his co-author, Jon­a­than Le­o of Lin­coln Me­mo­ri­al. They have al­so ar­gued that even if SS­RI’s did cure de­pres­sion, this would­n’t es­tab­lish that lack of ser­o­to­nin causes it, any more than as­pir­in’s ef­fi­ca­cy against headaches “proves” that lack of as­pi­rin causes headaches.

Courtesy Florida State Universityand World Science staff