Serotonin reuptake inhibitor

Single Dose Of Antidepressant Lexapro Can Change Brain’s Wiring In Just 3 Hours

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A single dose of Lexapro, a commonly prescribed SSRI antidepressant, quickly produces dramatic changes in the architecture of the human brain.Photo courtesy of Shutterstock

One out of every 10 Americans takes an antidepressant, according to the National Health and Nutrition Examination Survey, while one in every four women in their 40s and 50s do so. Now, a new study finds a single dose of a commonly prescribed SSRI (serotonin reuptake inhibitor) quickly produces dramatic changes in the architecture of the human brain. Specifically, brain scans taken of volunteers before and after one dose show a reduction of connectivity throughout the brain, with an increase of connectivity in two separate regions — all in just three hours.

What are SSRIs?

Worldwide, SSRIs are among the most widely prescribed form of antidepressants, often used to treat depression, anxiety disorders, panic attacks, and personality disorders. Classified as third-generation antidepressants, they are known for having fewer side effects than older pills and work by increasing levels of serotonin, a brain chemical naturally produced by your body. While serotonin serves many roles within your brain, chiefly it balances mood.

For the current study, 22 medication-free participants let their minds wander for about 15 minutes while their brains were scanned with an fMRI, a technology capable of measuring oxygenation of blood flow. Meanwhile, the researchers analyzed the three-dimensional images of each participant’s brain and measured the number of connections between small blocks of neurons known as voxels. After giving each volunteer a single dose of Lexapro (escitalopram), the researchers carefully observed the changes in those connections.

Immediately, the researchers felt surprised to discover the speed with which one dose of the SSRI performed. Within a matter of hours, it had reduced the level of intrinsic connectivity in most parts of the brain, while increasing connectivity within two regions: the cerebellum and thalamus. The cerebellum is responsible for, among other tasks, controling motor skills and balance, while the thalamus regulates consciousness, sleep, and alertness.

“We were not expecting the SSRI to have such a prominent effect on such a short timescale or for the resulting signal to encompass the entire brain,” said Dr. Julia Sacher of the Max Planck Institute for Human Cognitive and Brain Sciences and an author of the study. Sacher believes better understanding of the differences in individual response to SSRIs “could help to better predict who will benefit from this kind of antidepressant versus some other form of therapy.

Use of antidepressants near delivery and risk of postpartum hemorrhage: cohort study of low income women in the United States.

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Abstract

Objective To determine whether use of serotonin or non-serotonin reuptake inhibitors near to delivery is associated with postpartum hemorrhage.

Design Cohort study.

Setting 2000-07 nationwide Medicaid data (Medicaid Analytic eXtract).

Population 106 000 pregnant women aged 12-55 with a diagnosis of mood or anxiety disorder. Women were categorized into four mutually exclusive exposure groups according to pharmacy dispensing data: current (delivery date), recent (1-30 days before delivery date), past (1-5 months before delivery date), and no exposure (reference group).

Main outcome measures Risk of postpartum hemorrhage by timing of exposure and by serotonin or non-serotonin reuptake inhibitors, classes of antidepressant, and antidepressant types. Relative risks and 95% confidence intervals adjusted for delivery year, risk factors for postpartum hemorrhage, indicators of severity of mood/anxiety disorder, other indications for antidepressants, and other drugs. High dimensional propensity score (hdPS) methods were used to empirically identify and adjust for additional factors.

Results 12 710 (12%) women had current exposure to serotonin reuptake inhibitor monotherapy, and 1495 (1.4%) women had current exposure to non-serotonin reuptake inhibitor monotherapy. The risk of postpartum hemorrhage was 2.8% among women with mood/anxiety disorders but no exposure to antidepressants, 4.0% in the current users of serotonin reuptake inhibitors, 3.8% in the current users of non-serotonin reuptake inhibitors, 3.2% in the recent users of serotonin reuptake inhibitors, 3.1% in the recent users of non-serotonin reuptake inhibitors, 2.5% in the past users of serotonin reuptake inhibitors, and 3.4% in the past users of non-serotonin reuptake inhibitors. Compared with no exposure, women with current exposure to serotonin reuptake inhibitors had a 1.47-fold increased risk of postpartum hemorrhage (95% confidence interval 1.33 to 1.62) and women with current non-serotonin reuptake inhibitor exposure had a 1.39-fold increased risk (1.07 to 1.81). Results were similar with hdPS adjustment. Women with current exposure to serotonin reuptake inhibitors had an adjusted excess risk of 1.26% (0.90% to 1.62%), with a number needed to harm of 80, and for women with current exposure to non-serotonin reuptake inhibitors the excess risk was 1.03% (0.07% to 1.99%), with a number needed to harm of 97. For exposure to serotonin reuptake inhibitors the relative risk was 1.19 (1.03 to 1.38) for recent exposure and 0.93 (0.82 to 1.06) for past exposure; for non-serotonin reuptake inhibitors the figures were 1.17 (0.80 to 1.70) and 1.26 (1.00 to 1.59), respectively. Current exposure to selective serotonin reuptake inhibitor monotherapy was also associated with postpartum hemorrhage (1.42, 1.27 to 1.57), as was current serotonin norepinephrine (noradrenaline) reuptake inhibitor (1.90, 1.37 to 2.63) and tricyclic monotherapy (1.77, 0.90 to 3.47). All types of selective serotonin reuptake inhibitors available for analysis and venlafaxine, a serotonin norepinephrine reuptake inhibitor, were significantly associated with postpartum hemorrhage.

Conclusions Exposure to serotonin and non-serotonin reuptake inhibitors, including selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and tricyclics, close to the time of delivery was associated with a 1.4 to 1.9-fold increased risk for postpartum hemorrhage. While potential confounding by unmeasured factors cannot be ruled out, these findings suggest that patients treated with antidepressants during late pregnancy are more likely to experience postpartum hemorrhage.

Source: BMJ

 

Antidepressants Given Near Delivery Associated with More Postpartum Hemorrhage.

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Women exposed to antidepressants near the time of delivery show an increased risk for postpartum hemorrhage, according to a BMJ study.

Researchers analyzed Medicaid data on some 100,000 women with a diagnosis of mood or anxiety disorder. They used pharmacy dispensing data to characterize exposure, with “current exposure” defined as having a supply of antidepressant medicine on hand that overlapped with the delivery date.

Compared with nonexposed women (i.e., those having no drug supply within 5 months of the delivery date), those with current exposure showed a roughly 1.5-fold increased risk for postpartum hemorrhage. The authors calculate a number need to harm of 80 for patients on serotonin reuptake inhibitors and 97 for nonserotonin reuptake inhibitors.

They speculate that the effect could be partly explained by the effect of blocking serotonin reuptake in platelets, but the association with nonserotonin inhibiting drugs is “unexpected and should be confirmed.”

Soure: BMJ