Category: Antidepressants

Two aspects of personality linked to depression are changed by antidepressants.

Antidepressants can change two aspects of personality that are linked to depression, research finds.

Neuroticism — which is characterised by negative thinking in a range of areas — was reduced in people taking a common antidepressant.

At the same time, people’s extroversion was increased, making them feel more outgoing and sociable.

Extroversion is also linked to feeling more positive emotions.

The antidepressant tested in the study is called paroxetine, which is known commercially as Paxil and Seroxat, among other names.

The studies authors write:

“Patients taking paroxetine reported 6.8 times as much change on neuroticism and 3.5 times as much change on extraversion as placebo patients matched for depression improvement.”

For the study, 120 depressed patients took paroxetine and were compared to people given cognitive therapy and a placebo over 12 months.

All three groups saw improvements, even the placebo group.

However, only those taking the antidepressant experienced changes to their personality.

They authors explain:

“Neuroticism and extraversion are 2 of the 5 primary personality dimensions in the Five-Factor Model of Personality.

Neuroticism refers to a tendency to experience negative emotions and emotional instability; extraversion encompasses social extraversion, dominance, and a tendency to experience positive emotions.”

While antidepressants can be effective, still relatively little is known about how they work.

The study’s authors write:

“One possibility is that the biochemical properties of SSRIs directly produce real personality change.

Furthermore, because neuroticism is an important risk factor that captures much of the genetic vulnerability for major depressive disorder, change in neuroticism (and in neurobiological factors underlying neuroticism) might have contributed to depression improvement.”

The study was published in the journal Archives of General Psychiatry (Tang et al., 2009).

Do antidepressant do more harm than good?

While people are no more depressed now than they were 20 years ago, antidepressant use has tripled in this period.

Despite the surge, relatively little is known about how they work.

There is scant evidence that they ‘correct a chemical imbalance in the brain’, as drug marketers claim.

This raises many question, including:

• Do antidepressants do more harm than good?
• Do they really improve people’s quality of life compared with not taking them?
• How easy or hard is it to come off them?
• What is the best way to quit?

Below are 7 studies from the members-only section of PsyBlog that try to answer these questions, and more:

(If you are not already, find out how to become a PsyBlog member here.)

1. Antidepressants: Pros And Cons And How They Should Be Prescribed
2. How Antidepressants Affect Long-Term Quality Of Life
3. How Stopping Antidepressants Affects Relapse Risk
4. Depression NOT Caused By Low Serotonin Levels, Large Review Finds
5. The Real Risks Of Taking Antidepressants
6. The Best Way To Quit Antidepressants
7. Antidepressants Kill Positive Emotions Too: Why That’s Dangerous

.

For the first few weeks antidepressants have a strange side-effect researchers are trying to tackle.

It is popularly believed that SSRIs, like Prozac and Zoloft, only produce good feelings.

In fact, in the first few weeks of treatment, common antidepressants can cause increased anxiety and fear.

Serotonin — the neurotransmitter that is boosted by SSRIs — is even linked to suicidal thinking, especially in young people.

Research, though, could provide a clue as to how the effect can be reduced.

The serotonin-activated pathways in the brains of mice that lead to anxiety have been traced.

The circuit could be crucial to how SSRIs produce short-term anxiety.

Professor Thomas L. Kash, who led the research, said:

“The hope is that we’ll be able to identify a drug that inhibits this circuit and that people could take for just the first few weeks of SSRI use to get over that hump.

More generally, this finding gives us a deeper understanding of the brain networks that drive anxiety and fear behavior in mammals.”

Having identified the crucial circuit in the brain, the researchers moved on to trying to block it.

They were able to this with a ‘CRF blocker’, but as this research was in mice, it is not clear if the same result would be seen in humans.

Professor Kash said:

“It’s logical that it would since we know SSRIs can induce anxiety in people, and the pathways in these brain regions tend to be very similar in mice and humans.”

Professor Kash said:

“Other researchers are working to develop better CRF-inhibiting compounds, so that’s one potential direction to take, but there are others.

We’re now looking at the various proteins expressed by these BNST neurons, and we’re hoping to identify a receptor that is already targeted by established drugs.

One of them might be useful for people as they start taking SSRIs.”

The study was published in the journal Nature (Marcinkiewcz et al., 2016).

SSRI antidepressants such as Prozac and Zoloft can increase anxiety in the first few weeks.

Around 100 million people around the world take antidepressants like Prozac and Zoloft.

However, few are aware beforehand that antidepressants can worsen anxiety in the first few weeks of use.

Until recently scientists have found the side-effect mysterious.

Now, though, they have identified an anxiety circuit in the brain that responds to serotonin.

The study’s findings help underline the fact that serotonin does not just promote good feelings, despite what many think.

Professor Thomas L. Kash, who led the study, said:

“The hope is that we’ll be able to identify a drug that inhibits this circuit and that people could take for just the first few weeks of SSRI use to get over that hump.

More generally, this finding gives us a deeper understanding of the brain networks that drive anxiety and fear behavior in mammals.”

Anxiety worsened by SSRIs like Prozac And Zoloft

Studies have long suggested that serotonin can actually have negative effects on mood.

Younger people seem particularly vulnerable.

Scientists at the University of North Carolina (UNC) School of Medicine have now mapped out the pathway in the brain that is sensitive to serotonin and is linked to anxiety.

The regions of the brain are called the dorsal raphe nucleus (DRN) and the bed nucleus of the stria terminalis (BNST).

After activating these areas in mice using serotonin, the scientists observed anxiety-like behaviours.

Testing Prozac on these mice also showed that it made them more anxious.

Next the researchers hope to find a way of blocking the anxiety-inducing effects of antidepressants.

However, it will first need to be confirmed that human brains operate in a similar way to mice in this regard.

Professor Kash said:

“It’s logical that it would, since we know SSRIs can induce anxiety in people, and the pathways in these brain regions tend to be very similar in mice and humans.”

The study was published in the journal Nature (Marcinkiewcz et al., 2016).