Antidepressants

Antidepressants alone are not enough

Prozac Capsules

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We should reconsider how we use antidepressants more effectively. The latest studies have shown that antidepressants restore the capacity of certain areas of the brain to repair abnormal neural pathways. According to neuroscientist Eero Castrén, the recipient of EUR 2.5 million of ERC funding, recovery requires redirection of these pathways through practice, rehabilitation or therapy.

This is a surprisingly blunt view, even for a respected neuroscientist such as Eero Castrén. After all, millions of people throughout the world have been prescribed antidepressants, and pharmaceutical companies have made a billion-dollar business out of selling them. Surely the system cannot be entirely wrong?

Recent studies suggest that this may be the case. Research on animal models demonstrates that antidepressants are not a cure as such. Rather, their role is to restore plasticity in the adult brain. Antidepressants reopen a window of brain plasticity, which allows the formation and adaptation of brain connections through the patient’s own activities and observations, similarly to a young child whose brain and experiences about the world develop in response to environmental stimuli.

Correcting abnormal pathways

When cerebral plasticity is reopened, problems caused by false connections in the brain can be addressed. Such problems can be manifested, for example, as phobias. Studies conducted on animal models by Professor Eero Castrén’s research group at the University of Helsinki show that therapy helps to reduce fears for a time, but an antidepressant alone provides no relief. By combining the two, however, long-term effects can be achieved.

“Simply taking drugs is not enough. We must also show the brain what the desired connections should be,” Professor Castrén of the Neuroscience Centre explains.

The need for both therapy and medical treatment may also explain why antidepressants sometimes seem to have no effect. If the patient’s environment and situation remain unchanged, the drug-induced capacity of the brain to change will not make the patient feel better.

Reaching this point is the result of years of research. Scientists discovered as early as the 1960s that antidepressants affect neurotransmitters in the brain, such as serotonin. Later, antidepressants were found to increase neurotrophins and their ability to transmit signals in the brain. Only recently have scientists begun to explore the effects of drugs on plasticity of brain networks.

Enhancing the plasticity of the adult human brain through antidepressants has opened a whole new field of research for Eero Castrén. He has received a five-year grant of EUR 2.5 million from the European Research Council (ERC) to investigate mechanisms related to adult brain plasticity.

http://www.ncbi.nlm.nih.gov/pubmed/22194582

Full bibliographic information
Fear erasure in mice requires synergy between antidepressant drugs and extinction training.Karpova NN, Pickenhagen A, Lindholm J, Tiraboschi E, Kulesskaya N, Agústsdóttir A, Antila H, Popova D, Akamine Y, Bahi A, Sullivan R, Hen R, Drew LJ, Castrén E.Science. 2011 Dec 23;334(6063):1731-4

Source: Helsingin yliopisto (University of Helsinki)

Commonly prescribed anti-depressants appear to be doing patients more harm than good, say researchers who have published a paper examining the impact of the medications on the entire body.
“It’s important because millions of people are prescribed anti-depressants each year, and the conventional wisdom about these drugs is that they’re safe and effective.”

 

“We need to be much more cautious about the widespread use of these drugs,” says Paul Andrews, an evolutionary biologist at McMaster University and lead author of the article, published today in the online journal Frontiers in Psychology.

Andrews and his colleagues examined previous patient studies into the effects of anti-depressants and determined that the benefits of most anti-depressants, even taken at their best, compare poorly to the risks, which include premature death in elderly patients.
 
Anti-depressants are designed to relieve the symptoms of depression by increasing the levels of serotonin in the brain, where it regulates mood. The vast majority of serotonin that the body produces, though, is used for other purposes, including digestion, forming blood clots at wound sites, reproduction and development.

What the researchers found is that anti-depressants have negative health effects on all processes normally regulated by serotonin.

The findings include these elevated risks:

  • developmental problems in infants
  • problems with sexual stimulation and function and sperm development in adults
  • digestive problems such as diarrhea, constipation, indigestion and bloating
  • abnormal bleeding and stroke in the elderly

[continue reading…]

Prozac

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Study offers more proof for the power of placebo, say UCLA researchers

 
Individuals with major depressive disorder (MDD) often undergo multiple courses of antidepressant treatment during their lives. This is because the disorder can recur despite treatment and because finding the right medication for a specific individual can take time.

While the relationship between prior treatment and the brain’s response to subsequent treatment is unknown, a new study by UCLA researchers suggests that how the brain responds to antidepressant medication may be influenced by its remembering of past antidepressant exposure.

Interestingly, the researchers used a harmless placebo as the key to tracking the footprints of prior antidepressant use.

Aimee Hunter, the study’s lead author and an assistant professor of psychiatry at UCLA’s Semel Institute for Neuroscience and Human Behavior, and colleagues showed that a simple placebo pill, made to look like actual medication for depression, can “trick” the brain into responding in the same manner as the actual medication.

The report was published online March 23 in the journal European Neuropsychopharmacology.

The investigators examined changes in brain function in 89 depressed persons during eight weeks of treatment, using either an antidepressant medication or a similar-looking placebo pill. They set out to compare the two treatments — medication versus placebo — but they also added a twist: They separately examined the data for subjects who had never previously taken an antidepressant and those who had. [continue reading…]

Prozac Capsules

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Americans are no strangers to antidepressants. During the last 20 years the use of antidepressants has grown significantly making them one of the most costly and the third most commonly prescribed class of medications in the U. S. According to the Centers for Disease Control and Prevention, from 2005-2008 nearly 8.9 percent of the U.S. population had at least one prescription in this drug class during any given month. A new study led by researchers at the Johns Hopkins Bloomberg School of Public Health examines national trends in antidepressant prescribing and finds much of this growth was driven by a substantial increase in antidepressant prescriptions by non-psychiatrist providers without any accompanying psychiatric diagnosis. The results are featured in the August 2011 issue of Health Affairs.

Over the past two decades, the use of antidepressant medications has grown to the point that they are now the third most commonly prescribed class of medications in the United States. Much of this growth has been driven by a substantial increase in antidepressant prescriptions by non-psychiatrist providers without an accompanying psychiatric diagnosis. The analysis found that between 1996 and 2007, the proportion of visits at which antidepressants were prescribed but no psychiatric diagnoses were noted increased from 59.5 percent to 72.7 percent. These results do not clearly indicate a rise in inappropriate antidepressant use, but they highlight the need to gain a deeper understanding of the factors driving this national trend and to develop effective policy responses. To the extent that antidepressants are being prescribed for uses not supported by clinical evidence, there may be a need to improve providers’ prescribing practices, revamp drug formularies, or vigorously pursue implementation of broad reforms of the health care system that will increase communication between primary care providers and mental health specialists.

Source: Johns Hopkins Bloomberg School of Public Health
Health Affairs