©Copyright 2011 Paula J. Caplan All rights reserved
How often do we hear: "If you want to lose weight, all you have to do is eat less and exercise more"? It sounds so simple.
To read press releases about weight-loss programs, to hear First Lady Michelle Obama and commentators in broadcast media talk, one would think that the reasons are threefold: too much fast food, food portions of all kinds that are too large, and sedentary lifestyle. No doubt all three play significant roles, as does poverty - because healthy food tends to be more expensive than foods that cause weight gain - which is occasionally.
But an elephant in the living room is the role of psychiatric drugs. "Elephant in the living room," if you haven't heard the expression, means what is right in front of one's eyes, although one acts as though it is not there. The increase in Americans' weight has come during the time of the dramatic increase in prescriptions of psychiatric drugs in this country, and many of those drugs are known to cause sudden, massive weight gain. To look at both public and, in large measure, medical researchers' and clinicians' pronouncements about obesity, you would never know that these drugs might play a role in the "obesity epidemic," because they are not mentioned as one contributing factor.
To walk into any place that is populated by people who are or have been patients/clients/consumers in the mental health system is to notice that the weight of the average person present seems strikingly higher than that of the average American. This pattern is all the more striking in light of the ubiquitous expressions of alarm and presence of programs designed to combat what's now always called the American obesity epidemic because the average American's weight has substantially risen in recent years.
Many drugs marketed as anti-depressants, mood stabilizers, and anti-psychotics can cause extreme weight gain. As just one example, after Alaska attorney James Gottstein helped make public Eli Lilly's internal documents about the drug Zyprexa, the manufacturer added to the label the information that one out of six patients will gain an average of 33 pounds in their first two years on the drug.  Given such cause-effect relationships between many drugs and weight gain, the usual invisibility of drugs as contributing factors is particularly puzzling.
The mechanisms that lead from drug intake to weight gain are not yet fully understood, but some are thought to impair the central nervous system's control over energy intake, others are thought to affect metabolic rate and leptin levels, and there are probably other mechanisms related to other medications. One reason that so little is known is that drug manufacturers tend to focus their research, as well as their often selective reporting of research, on the effects that they hope a new drug will have rather than the whole array of effects it can have on individuals. And individual variability is known to characterize reactions to drugs of many kinds, not just psychotropic ones.
Even while we wait for further research about these mechanisms, however, we might wonder what explains the near blackout of mention of the cause-effect connection between psychiatric drugs and increases in weight. PBS is not usually assumed to be commercially-driven, yet a major PBS special called "Fat: What No One Is Telling You"  included a wide array of lifestyle and physiological factors...with no mention of psychiatric drugs. And Ms. Obama's campaign, like that of former President Bill Clinton when he advocated removing candy and pop machines from schools, is characterized by that same absence.
If the failure to consider this connection is alarming in general, how much more so is the failure to consider it for children and adolescents, given that prescriptions of psychotropic drugs for them has skyrocketed in the past two decades.
It is impossible not to wonder whether the enormous financial and political power of the pharmaceutical companies plays a role in the covering-up of the cause-effect relationship between drugs and poundage. As media consumers, readers of self-help weight-loss books, and constituents of politicians who advocate weight-loss programs, we can take two important steps: We can educate ourselves and others about which drugs affect weight, and we can insist that publicly-funded weight-loss programs include at least some attention to these drugs' effects.
 See Paula J. Caplan. (2008). The pills that make us fat. New Scientist. March 8, p. 18.