探花直播 of Cambridge - antidepressants

Scientists explain emotional 鈥榖lunting鈥� caused by common antidepressants

cjb250 — Mon, 23 Jan 2023 06:00:50 +0000

According to the NHS, more than 8.3 million patients in England received an antidepressant drug in 2021/22. A widely-used class of antidepressants, particularly for persistent or severe cases, is selective serotonin reuptake inhibitors (SSRIs). These drugs target serotonin, a chemical that聽carries messages between nerve cells in the brain and has been dubbed the 鈥榩leasure chemical鈥�.

One of the widely-reported side effects of SSRIs is 鈥榖lunting鈥�, where patients report feeling emotionally dull and no longer finding things as pleasurable as they used to. Between 40-60% of patients taking SSRIs are believed to experience this side effect.

To date, most studies of SSRIs have only examined their short term use, but, for clinical use in depression these drugs are taken chronically, over a longer period of time. A team led by researchers at the 探花直播 of Cambridge, in collaboration with the 探花直播 of Copenhagen, sought to address this by recruiting healthy volunteers and administering escitalopram, an SSRI known to be one of the best-tolerated, over several weeks and assessing the impact the drug had on their performance on a suite of cognitive tests.

In total, 66 volunteers took part in the experiment, 32 of whom were given escitalopram while the other 34 were given a placebo. Volunteers took the drug or placebo for at least 21 days and completed a comprehensive set of self-report questionnaires and were given a series of tests to assess cognitive functions including learning, inhibition, executive function, reinforcement behaviour, and decision-making.

探花直播results of the study are published today in Neuropsychopharmacology.

探花直播team found no significant group differences when it came to 鈥榗old鈥� cognition 鈥� such as attention and memory. There were no differences in most tests of 鈥榟ot鈥� cognition 鈥� cognitive functions that involve our emotions.

However, the key novel finding was that there was reduced reinforcement sensitivity on two tasks for the escitalopram group compared to those on placebo. Reinforcement learning is how we learn from feedback from our actions and environment.

In order to assess reinforcement sensitivity, the researchers used a 鈥榩robabilistic reversal test鈥�. In this task, a participant would typically be shown two stimuli, A and B. If they chose A, then four out of five times, they would receive a reward; if they chose B, they would only receive a reward one time out of five. Volunteers would not be told this rule, but would have to learn it themselves, and at some point in the experiment, the probabilities would switch and participants would need to learn the new rule.

探花直播team found that participants taking escitalopram were less likely to use the positive and negative feedback to guide their learning of the task compared with participants on placebo. This suggests that the drug affected their sensitivity to the rewards and their ability to respond accordingly.

探花直播finding may also explain the one difference the team found in the self-reported questionnaires, that volunteers taking escitalopram had more trouble reaching orgasm when having sex, a side effect often reported by patients.

Professor Barbara Sahakian, senior author, from the Department of Psychiatry at the 探花直播 of Cambridge and a Fellow at Clare Hall, said: 鈥淓motional blunting is a common side effect of SSRI antidepressants. In a way, this may be in part how they work 鈥� they take away some of the emotional pain that people who experience depression feel, but, unfortunately, it seems that they also take away some of the enjoyment. From our study, we can now see that this is because they become less sensitive to rewards, which provide important feedback.鈥�

Dr Christelle Langley, joint first author also from the Department of Psychiatry, added: 鈥淥ur findings provide important evidence for the role of serotonin in reinforcement learning. We are following this work up with a study examining neuroimaging data to understand how escitalopram affects the brain during reward learning.鈥�

探花直播research was funded by the Lundbeck Foundation.

Reference
Langley, C, Armand, S, et al. Chronic escitalopram in healthy volunteers has specific effects on reinforcement sensitivity: A double-blind, placebo-controlled semi-randomised study. Neuropsychopharmacology; 23 Jan 2023; DOI: 10.1038/s41386-022-01523-x

Scientists have worked out why common anti-depressants cause around a half of users to feel emotionally 鈥榖lunted鈥�. In a study published today, they show that the drugs affect reinforcement learning, an important behavioural process that allows us to learn from our environment.

Ethan Sykes

Man looking out of window

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Antidepressant use more than doubles among over 65s in two decades

cjb250 — Mon, 07 Oct 2019 08:54:57 +0000

Despite this rise in antidepressant use, there has been little change in the number of older people diagnosed with depression.

探花直播findings are based on the Cognitive Function and Ageing Studies, conducted at two time points - between 1991 and 1993, and between 2008 and 2011.聽

First author Prof Antony Arthur, from UEA鈥檚 School of Health Sciences, said: 鈥淒epression is a leading cause of poor quality of life worldwide and we know that older people may be less likely than other age groups to go to their GP with symptoms of depression.聽Until now, little was known about how the relationship between the prevalence of depression and antidepressant use among older people has changed over time.鈥�

探花直播Cognitive Function and Ageing Studies (CFAS), led by the 探花直播 of Cambridge, are population based studies of individuals aged 65 with the ability to examine changes in the health needs of older people across generations based on random sampling and diagnostic methods held constant over time.

As part of CFAS, researchers interviewed more than 15,000 over 65s in England and Wales to see whether the prevalence of depression and antidepressant use is changing. They found that the proportion of older people receiving anti-depressant medication more than doubled over two decades 鈥撀爁rom 4.2聽per cent in the early nineties to 10.7 per cent 20 years later. This was despite the estimated prevalence of depression among over 65s falling to 6.8 per cent compared to 7.9 per cent in the 1990s.

Depression and antidepressant use were more common in women than men at both time points.聽Depression was associated with living in a more deprived area. 探花直播proportion of over 65s living in care homes declined, but prevalence of depression in care homes remained unchanged 鈥� affecting around one in ten residents.

Lead investigator Prof Carol Brayne, director of the Cambridge Institute of Public Health, said: "Our research has previously shown a major age-for-age drop in dementia occurrence across generations. This new work reveals that depression has not shown the same reduction even in the presence of dramatically increased prescribing, itself not without concern given potential adverse effects we have also shown that are associated with polypharmacy."

Prof Arthur said: 鈥淒epression affects one in 15 people aged over 65, and its impact is felt by the individual, their families and friends.

鈥淸探花直播increase in antidepressant use] could be due to improved recognition and treatment of depression, overprescribing, or use of antidepressants for other conditions. Whatever the explanation, substantial increases in prescribing has not reduced the prevalence of depression in the over-65 population. 探花直播causes of depression in older people, the factors that perpetuate it, and the best ways to manage it remain poorly understood and merit more attention.鈥�

探花直播research was led by the 探花直播 of East Anglia in collaboration with the 探花直播 of Cambridge, the 探花直播 of Newcastle and the 探花直播 of Nottingham.

Reference
Arthur, A. et al. Changing prevalence and treatment of depression among the over-65s over two decades: findings from the Cognitive Function and Ageing Studies. British Journal of Psychiatry; 7 Oct 2019; DOI: 10.1192/bjp.2019.193

Adapted from a press release by the 探花直播 of East Anglia.

探花直播proportion of people aged over 65 on antidepressants has more than doubled in two decades, according to new research led by the 探花直播 of Cambridge and 探花直播 of East Anglia (UEA).

Our research has previously shown a major age-for-age drop in dementia occurrence across generations. This new work reveals that depression has not shown the same reduction even in the presence of dramatically increased prescribing

Carol Brayne

James Hose Jr

Elderly couple

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Antidepressants and pain killers: should we be worried?

cjb250 — Wed, 15 Jul 2015 08:00:15 +0000

Many of us frequently take pain killers to relieve our headaches, to soften joint pains or to reduce the symptoms of a cold. Some of these drugs 鈥� for example, ibuprofen, but not paracetamol 鈥� are from a class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs). These medicines are very commonly used 鈥� in fact, they are amongst the top-twenty most frequently prescribed medications in UK primary care. Non-prescription use is also widespread, with many products available off the shelf in supermarkets and without oversight from a pharmacist.

Antidepressants medication use is also commonplace, although in the UK these are prescription only medicines. Importantly, depression and chronic pain frequently co-exist: roughly a third of those with a painful condition also experience depression, and over a quarter of those suffering depression also complain of pain.

A paper out this week in the BMJ has identified an increased risk of brain haemorrhage from the combined use antidepressants and NSAIDS. This will understandably raise concerns amongst both doctors and the public. But is it that straightforward?

There is already an established risk of gastrointestinal bleeding, for example in the lining of the stomach, with this combination of drugs 鈥� probably greater than the newly identified risk of brain haemorrhage. Yet it is likely many GPs (and probably other doctors) remain unaware of this problem, and it does not influence the majority of prescribing behaviour anyway. So does this new found problem matter, or will it be interpreted by many as simply relatively unfounded scaremongering?

We mustn鈥檛 lose sight of the fact that the risk of brain haemorrhage is still low: over a period of 30 days taking both antidepressants and NSAIDS, only one person in every 2,000 would be affected. And given the absolute benefits of antidepressants and NSAIDs are generally not easily quantified, and need to be interpreted in the context of the individual鈥檚 personal psychological and social circumstances, the balance of harm and benefit remains uncertain.

Doctors will also understandably ask what the alternatives are: there are limited options for chronic pain relief, and NHS access to psychological treatments for depression (for example cognitive behavioural therapy, CBT), is generally poor. Patients鈥� quality of life will often be significantly diminished by stopping these medicines.

And there are several important unanswered questions remaining. What are the longer-term risks, beyond the first month examined by the current study? What is the risk of the drugs when used separately? And can these findings from an East-Asian population be generalized to the rest of the world, given what we know that people of different ethnic backgrounds often respond to medicines differently? There is a need for further research to answer these uncertainties.

Overall, this new paper identifies a potential small risk of adverse consequences of combining two common drugs, but unresolved queries remain. For now, if people are worried about the medications they are taking, they should discuss their concerns with their doctor, even if doctors then find themselves in the difficult position of trying to explain the uncertain balance of risks and benefits to patients.

But these issues are also important and very relevant to the safe and rational use of medicines more generally. It is not uncommon for patients to be affected by more than one condition 鈥� depression, arthritis, diabetes, heart disease, for example 鈥� and hence taking a mixture of drugs. We need further research to better understand the challenges associated with using combinations of medicines in people with multiple health conditions.

Reference
Risk of intracranial haemorrhage linked to co-treatment with antidepressants and NSAIDs. BMJ; 15 July 2015

New research has identified an increased risk of brain haemorrhage from the combined use of antidepressant medicines and medicines such as ibuprofen. Should we be worried? Dr Rupert Payne from the Cambridge Centre for Health Services Research looks at the evidence.

If people are worried about the medications they are taking, they should discuss their concerns with their doctor

Rupert Payne

Robson#

Pills here (cropped)

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Study suggests new treatment for impulsivity in some dementia patients

cjb250 — Thu, 25 Jun 2015 08:10:21 +0000

Around 16,000 people in the UK are estimated to be affected by frontotemporal dementia (also known as Pick鈥檚 disease). Patients are often affected at a young age, 50-65 years old. 探花直播disease affects the frontal and temporal lobes of the brain, at the front with both shrinkage and loss of important brain chemicals like serotonin. As a result, symptoms of frontotemporal dementia include changes in personality and behaviour, and difficulties with language.

One of the key symptoms is disinhibition 鈥� impulsivity and impetuous behaviour. This is partly a result of a deficiency in serotonin, an important chemical within the brain which is responsible for maintaining normal behaviour as well as mood.

A team led by Dr James Rowe from the 探花直播 of Cambridge and the Medical Research Council (MRC) Cognition and Brain Sciences Unit at Cambridge looked at whether citalopram, a commonly-prescribed antidepressant, might restore the brain function 鈥� and potentially alleviate the symptoms of disinhibition. Citalopram is known to restore levels of serotonin, even in patients who do not have depression; this increase in serotonin helps the brain activity needed make decisions about what to do, and what not to do.

探花直播researchers examined the brain activity associated with disinhibition in patients and healthy volunteers. 探花直播patients received either a dose of citalopram or a placebo, in a double-blinded placebo-controlled trial. Participants took part in a 鈥楪o-NoGo鈥� task whilst their brain activity was monitored using a combination of magnetoencephalography (MEG) and electroencephalography (EEG). In the task, the volunteers needed to intermittently hold back from a habitual action, choosing to press or not to press buttons.

As expected, patients with frontotemporal dementia made many errors on the task, with difficulty holding back from actions. 探花直播performance on the task was closely related to their everyday impulsive and disinhibited behaviours.聽 Compared to the placebo, citalopram boosted activity in the dementia patients in their right inferior frontal gyrus, a critical region of the brain for controlling our behaviour, even though this part of the brain was shrunken by the disease.

Dr Laura Hughes from the 探花直播 of Cambridge and the MRC Cognition and Brain Sciences Unit, first author on the study, says: 鈥淭his is a very promising result, which builds on a lot of basic laboratory science here in Cambridge. It suggests that it may be possible to treat patients safely and effectively for high risk and challenging impulsive behaviours, although more work is needed to identify those who are most likely to benefit from this type of drug.鈥�

探花直播research was primarily funded by the Wellcome Trust with additional support from the Medical Research Council and the NIHR Cambridge Biomedical Research Centre.

Reference
Hughes, LE et al. Improving response inhibition systems in frontotemporal dementia with citalopram. Brain; e-pub 22 May 2015

Restoring the low levels of the chemical serotonin may help improve brain function and reduce impulsivity in some dementia patients, according to Cambridge researchers. A study published in the July edition of the journal Brain suggests a potential new treatment for people affected by frontotemporal dementia.

This is a very promising result, which suggests that it may be possible to treat patients safely and effectively for high risk and challenging impulsive behaviours

Laura Hughes

NOAA's National Ocean Service

Brain coral

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Antidepressants can alter peoples鈥� moral judgement

bjb42 — Tue, 28 Sep 2010 00:00:00 +0000

探花直播new research, by scientists at the 探花直播 of Cambridge's Behavioural and Clinical Neuroscience Institute, discovered that healthy volunteers given drugs which increase their serotonin, selective serotonin reuptake inhibitors (SSRI), have an increased aversion to harming others, viewing such actions as morally forbidden.

Ms Molly Crockett of the Behavioural and Clinical Neuroscience Institute (a Medical Research Council and Wellcome Trust funded initiative) is the lead author of the paper. She said: "Our study suggests that these medications can affect people's sense of right and wrong, which influences the choices they make in everyday life.

"Interestingly, the drug's effects were strongest in people who were naturally high in empathy, suggesting that serotonin could enhance people's concern for others by making the prospect of harming them feel worse."

Antidepressants, which include SSRIs like the one used in the study, are among the most widely prescribed drugs worldwide. In the United States and the UK, an estimated ten per cent of the population take antidepressants for a range of psychiatric and medical conditions.

探花直播Cambridge researchers measured the drug's effects on moral judgement by giving the participants 'dilemmas' which pitted beneficial outcomes (e.g., saving five lives) against highly unpleasant harmful actions (e.g., killing an innocent person). Individuals with increased serotonin were far more likely to judge the harmful actions as morally wrong even when such actions would result in significant benefits.

探花直播participants' aversion to harming others, on the grounds that it was morally objectionable, was also apparent on a different test in which subjects decide whether to accept or reject fair or unfair splits of a sum of money from another player. People tend to reject unfair offers as an act of retaliation, because rejecting offers harms the other player financially. Subjects taking the SSRI were less likely to reject unfair offers, possibly because they were reluctant to hurt the other players financially.

A previous study by the same research group had found that decreasing serotonin made people more likely to retaliate against unfairness.

探花直播most common type of antidepressants, serotonin enhancers, alters peoples moral judgement and leads to a reduction in aggressive behaviour, a study published today in the journal Proceedings of the National Academy of Sciences (PNAS) has found.

Our study suggests that these medications can affect people's sense of right and wrong, which influences the choices they make in everyday life.

Molly Crockett

Amanda Hatfield

Antidepressants

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