This constant worry affects daily functioning and can cause physical symptoms. For a diagnosis to be made, worry must be present more days than not for at least six months.
GAD frequently co-occurs with mood disorders, including depression. About Lexapro Lexapro is the newest and fastest-growing selective serotonin reuptake inhibitor SSRI and is prescribed for more than four million patients in the U. Lexapro was approved by the U. Food and Drug Administration FDA in August for both the initial and maintenance treatment of major depressive disorder.
Lexapro is available as tablets and oral solution. Forest Laboratories licenses Lexapro from H. Cell Biology Neurobiology. Prestigious award for the pioneers of optogenetics September 24, Awards Medicine Neurobiology. Programming synthetic exosomes to optimize wound healing September 03, Medicine Synthetic Biology.
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Taking the brain out for a walk July 15, Brain Medicine Psychology. Risk factors for depression are less decisive in old age June 03, By preventing a protein called serotonin transporter SERT form absorbing the serotonin back into neurons that release it, the drugs boost serotonin levels in the junctions between cells.
But the details of this mechanism have long eluded researchers, who have sought to crystallize and visualize the SERT protein since the early s. Gouaux and his colleagues finally succeeded by creating small mutations in the SERT gene to make the protein more stable. For the first time, they were able to see the pocket in which two SSRIs — Paxil paroxetine and Lexapro escitalopram — bind. They also identified a second pocket, called an allosteric site.
When escitalopram binds to both sites, the transporter protein and the drug bond more tightly, which increases the medicine's effect. Understanding the structure, he says, could lead to the development of more-effective depression drugs with fewer side effects. Over the past decade, most major pharmaceutical companies have ceased research into and development of new psychiatric drugs — a task that has proven to be complicated, expensive and fruitless.
In the meantime, thinking about what actually causes mental illness has shifted. Researchers no longer believe that depression is solely caused by low levels of serotonin or other signalling molecules in the brain, says Richard Friedman, a psychiatrist at Weill Cornell Medical College in New York City.
Rather, some types of depression involve abnormal serotonin levels in certain parts of the brain, he says, which may help to explain why SSRIs do not work for everyone. Yet Friedman and others still find the latest paper exciting. Gouaux says that his team and others are looking at naturally occurring mutations in SERT that may predispose some people to be more or less prone to depression.
Researchers are also working to crystallize the transporter proteins for two other neurotransmitters — dopamine and norepinephrine. Understanding these differences may elucidate the broader roles that various neurotransmitters have in mental illness and drug addiction.
Molecules such as cocaine bind to and block DAT, which increases dopamine levels outside the cell. Jacobson and his colleagues found a group of small molecules that can enhance this interaction by binding to the allosteric site. These findings could lead to better drugs for dopamine-deficiency problems, such as attention-deficit hyperactivity disorder. But in the meantime, researchers and patients are left waiting for other discoveries that might pin down the exact cause of depression.
Coleman, J. Carlsson, A.
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