Antidepressants may alter personality

December 9, 2009

New research finds that antidepressants may alter personality, making those who suffer from depression more extraverted and less neurotic. Tony Tang, PhD, lead study author and adjunct psychology professor at Northwestern University, says changes in these personality traits could help prevent future relapses of depression.

According to HealthDay, relapsing after receiving treatment for depression has been found to be a major problem for sufferers. Approximately two-thirds of patients relapse after stopping medication, while almost half of patients suffer a relapse while they are still in the process of being treated.

It has been thought that patient personality changes were the result of antidepressants improving mood. However, Science News reports that this new research suggests that SSRIs (selective serotonin reuptake inhibitors) have an independent effect on these personality traits which in turn helps to ease depression.

The study, published in the Archives of General Psychiatry, consisted of 240 adults with severe depressive disorders. The participants were divided intro three groups – 120 took Paxil (paroxetine), sixty received cognitive therapy, and the other sixty took a placebo. Personalities were assessed before, during and after the treatment had been completed.

Health.com reports that the level of extraversion reported by the Paxil group was 3.5 times greater than the other two groups, and the reduction in neuroticism was seven times greater.

Lead researcher Tang says:

“People’s personalities actually do change and quite substantially when they go through these antidepressant treatments…In the past, we tended to dismiss the personality changes as a side effect or something not very important. But our study suggests it’s actually very important to treatment outcomes.”


Pharma and crime (it’s not what you think)

September 29, 2009

A notable drop in crime in the U.S. in the 1990s, particularly violent crime, appears to have been mirrored by the introduction of new and more effective drugs to treat mental illness. That’s the conclusion of an intriguing National Bureau of Economic Research working paper, which takes as its starting point the fact that many of the presumed social, economic, and policy determinants of crime actually had little impact on this change, and so other factors may be responsible. As the authors note,

“One factor that has so far been ignored in the attempt to explain this recent drop in crime is a period of dramatic technological advances in the treatment of mental illness. As we summarize below, mental illness is a clear risk factor both for criminal behavior and for victimization. The decline in crime rates occurred during a period when many new pharmaceutical therapies became available to treat mental illness, resulting in exceptionally large increases in medical treatment of mental illness. For example, during the last two decades the use of antidepressants and anti psychotics has become increasingly common following a series of drug innovations in the late 1980s and early 1990s. The new drugs were marked improvements over the previous therapies in terms of side effects and efficacy, and their use has subsequently become widespread. Anti-depressants and anti-psychotic medications are now the 6th and 7thlargest therapeutic classes of drugs sold globally (IMS Health 2006), and by 2005 there were enough newer anti-depressants sold in the U.S to treat every man, woman, and child with a daily dose for almost two months.”

As the authors point out, it has long been established that people likely to engage in criminal behavior respond to incentives, but any such assessment of the risks and benefits may be undercut by mental illness.

“Mental illness may cause the afflicted to substantially discount the future, thereby lowering the deterrent effect of established punishments. This possibility is substantially related to Becker and Mulligan’s (1997) formulation of impatience. They observe that many people recognize their high rate of time preference as a weakness, and allocate resources to overcome that weakness. One might think of mental health treatment as just such an allocation. The expansion of treatment for mental illness can then affect crime not by changing the certainty or severity of punishment, but by changing the behavioral response to established costs.”

Given that severe mental illness is associated with delusional thinking, poor impulse control, narcissism, and altered perceptions of risk, it is not surprising to find correlational studies showing that those with severe mental illness are much more likely to be incarcerated in the past six months than comparable people in the general population. A study that followed all the children born in Dunedin, New Zealand over the course of a year found that those with mental illness were twice as likely to be violent.

So how much of an effect has the psycho-pharmacological revolution had on crime? The authors note that their paper is only a first step in an area of limited data, but they did find that “prescriptions for stimulants and antipsychotics [were] associated with relatively large reductions in violent crimes: 0.129 percent and 0.085 percent for every 1 percent increase in stimulants and antipsychotics, respectively.” The findings were statistically significant.

They also tested their model with the increased use of statins for cholesterol, to see if there findings might be confounded by broader changes in health care.  As the authors note, the growth  of drugs such as Lipitor and Crestor “was likely shaped by some of the same social, economic and policy conditions that led to the rise in pharmaceutical treatment of mental illnesses.”  The relationship between crime and statins was insignificant (and in some cases, positive).

Their conclusion of this long and fascinating paper are noteworthy:

“Our evidence suggests that, in particular, sales of new generation antidepressants and stimulants used to treat ADHD are associated with rates of violent crime, with weaker evidence that anti-psychotic medications played a role in declining crime rates. The magnitude of the elasticities estimated here are clearly small. We estimate that a one percent increase in the total prescription rate is associated with a 0.051 percent decrease in violent crimes. To put this in perspective, doubling the prescription rate would reduce violent crimes by 5 percent, or by about 27 crimes per 100,000, at the average rate of 518 crimes per 100,000 population. While doubling the prescription rate seems like a large change, it has been estimated that 28 percent of the U.S. adult population in any year has a diagnosable mental or
addictive disorder, yet only 8 percent seeks treatment (USDHHS 1999). Doubling the treatment rate would still leave a substantial portion of the ill untreated.”

hat tip – Andrew Sullivan


Antidepressant use doubles in America

August 5, 2009

A new study finds that the use of antidepressants has almost doubled among people in the U.S. between the years 1996 and 2005 – increasing from 5.84 percent to 10.12 percent. That translates to a grand total of 27 million people.

In order to conduct this study, the authors Dr. Mark Olfson and Dr. Steven C. Marcus examined the Medical Expenditure Panel Surveys completed in 1996 and 2005 by the U.S. Agency for Healthcare Research and Quality. The surveys help to provide estimates about healthcare costs and consisted of approximately 50,000 people age  six and over.

After examining the data, the research team noticed that this significant increase did not hold true for African Americans (3.61 percent in 1996 to 4.51 percent in 2005) or Hispanics (3.72 percent in 1996 to 5.21 percent in 2005). They also found that the number of people taking part in therapy decreased from 31.5 percent to 19.87 percent, while the patients prescribed antipsychotic medications rose from 5.46 percent to 8.86 percent.

Dr. Mark Olfson tells HealthDay:

“The reasons [for the growth] are unclear but they may include the introduction of new antidepressants over the last 10 to 12 years or so and a broadening in the clinical indications of antidepressant treatment. Years ago, these drugs were largely focused on depression. Today, more different conditions are treated with antidepressants… There’s also been an increase in direct-to-consumer advertising and a lessening of the stigma associated with seeking mental health care.”

The study authors found a considerable increase in direct-to-consumer advertising, from $32 million in 1996 to $122 million in 2005. This is evident through the influx of television advertisements for antidepressants shown in recent years. (Does anyone else find the recent commercial with the woman and her wind up toy slightly creepy?)

Now that antidepressants are the most prescribed category of drugs in the U.S., Olfson expresses concern that these prescriptions might be taken too casually. He emphasizes to WebMD that the decision to take an antidepressant is between the physician and the patient and should be taken seriously in order to determine the best treatment plan.

The study is published in the Archives of General Psychiatry and more information on depression can be found here.


What the Media Misses About Antidepressants

February 27, 2008

A recent meta-analysis in Britain was reported as showing that certain anti-depressants, namely SSRIs, are no better than a placebo in treating depression. STATS Maia Szalavitz explains on Scientific American why the coverage of this study misses the salient point: “when you are looking at aggregated data, huge individual differences can be washed out.”

Some people are strong responders to one drug –but give them another in the same class, and they become actively suicidal. Most people have a slight positive effect; some have a slight negative effect. In aggregate, a drug that is a home run for one person and potentially fatal to another looks inert.

More at Scientific American’s 60- Second Science.


Antidepressants: Hiding Studies That Find No Result or Ignoring Poorly Designed Studies?

January 17, 2008

Trevor Butterworth

The New England Journal of Medicine has just published an interesting and possibly disturbing study showing that the anti-depressants Prozac and Paxil may be less effective than previously thought because studies showing their lack of efficacy were never published or incorporated into overall reviews of the drugs. As the New York Times reports:

In published trials, about 60 percent of people taking the drugs report significant relief from depression, compared with roughly 40 percent of those on placebo pills. But when the less positive, unpublished trials are included, the advantage shrinks: the drugs outperform placebos, but by a modest margin, concludes the new report, which appears Thursday in The New England Journal of Medicine.

Previous research had found a similar bias toward reporting positive results for a variety of medications; and many researchers have questioned the reported effectiveness of antidepressants. But the new analysis, reviewing data from 74 trials involving 12 drugs, is the most thorough to date. And it documents a large difference: while 94 percent of the positive studies found their way into print, just 14 percent of those with disappointing or uncertain results did.

It’s important to note that the authors of this study were not able to investigate the reasons for non-publication:

“We cannot determine whether the bias observed resulted from a failure to submit manuscripts on the part of authors and sponsors, from decisions by journal editors and reviewers not to publish, or both.”

There might be good reasons why some of the trials were not published – poor design for example. And without that kind analysis, which this NEJM study doesn’t provide, the idea that the manufacturers were engaged in some sort of conspiracy to cover up data detrimental to selling their products remains unproven.

Still, the significance in metal analysis of failing to account for studies that find no result was highlighted by the research which claimed the diabetes drug Avandia was associated with an increased risk for heart attack. When studies which didn’t find an association were factored into the meta analysis, this increase in risk disappeared.

Dare we bring up the irony that both the New England Journal of Medicine, which published the Avandia study by cardiologist Steve Nissen, and the New York Times, which gave it significant coverage both on the news pages and on the editorial pages, overlooked this confounding absence, even when it began to be the subject of widespread criticism?


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