SSRI Antidepressants: Impact on immune system according to scientists

[Guest guest]

SSRI-Research@

Fri, 27 Jan 2006 20:26:15 -0800 (PST)

[sSRI-Research] SSRI Antidepressants: Impact on immune system

according to scientists

 

 

 

 

http://www.redherring.com/Article.aspx?a=393 & hed==Uppers+Might+Impact+Immunity & \

sector==Regions & subsector==Americas

 

 

A major class of anti-depressant drugs including Prozac and Paxil may

impact patients´ immunity.

January 19, 2006

 

A major class of antidepressant drugs that includes brand names like

Prozac and Paxil might impact the immune system in unknown ways,

researchers said Thursday, adding that further research needs to be

done on the potential effects.

 

The scientists at Georgetown University in Washington, D.C. made the

claim after discovering that a chemical used to communicate between

different nerve cells in the brain is also passed between important

immune system cells.

 

" The wider health implication is that commonly used SSRI

antidepressants, which target the uptake of serotonin into neurons,

may also impact the uptake in immune cells, " said Gerard Ahern,

assistant professor of pharmacology at Georgetown. " It is something

that should be explored because we really have no idea what SSRI´s are

doing to people´s immune systems. "

 

SSRI´s (selective serotonin reuptake inhibitors) include major brands

of antidepressants, including Eli Lilly´s Prozac, Pfizer´s Zoloft, and

GlaxoSmithKline´s Paxil. They constitute the sixth bestselling class

of drugs sold in the United States in the 12 months up to June 2005,

according to IMS Health. This translates to three percent of all U.S.

drugs by sales, or a $7.5 billion market.

 

U.S. sales of Zoloft reached $3.1 billion in the year leading up to

June 2005.

 

The drugs work because they increase levels of serotonin in the brain

by preventing it from being " mopped up, " which helps neurons

communicate in order to generate positive and pleasurable feelings.

 

" At this point we just don´t know how these drugs might affect

immunity, so we really need to clarify the normal role of serotonin in

immune cell functioning, " said Professor Ahern.

 

The effect on the immune system could be good or bad. On the one hand,

the compounds could act to bolster the immune system function in

depressed people in such a way that it reduces their susceptibility to

infection. But they could also boost it to the extent where the immune

system starts attacking itself, a condition called autoimmune disease.

 

The researchers discovered that components of the immune system called

dendritic cells employ serotonin as part of their method of telling

T-cells to set into play the immune system´s pathogen destruction

response.

 

Therefore, SSRI´s " likely change some of the parameters of T-cell

activation, " said Professor Ahern. " But we don´t know yet if it

enhances or inhibits the total immune response. "

 

Following this finding, the researchers are now carrying out animal

experiments to find out more about the phenomenon in living cells.

 

RELATED ARTICLES

 

 

 

Adult Suicides Linked to Paxil

A new analysis reports that Glaxo´s antidepressant is associated with

a higher risk of suicide in adults.