Featured Research

from universities, journals, and other organizations

Psychiatric Symptoms May Signal Brain Damage From Diet Pills

Date:
August 28, 1997
Source:
National Institute Of Mental Health
Summary:
Users of widely prescribed diet pills may suffer irreversible loss of brain serotonin nerve terminals, possibly resulting in symptoms of anxiety, depression, cognitive and sleep problems, suggests the first author of a newly published report on fenfluramine side effects.

Users of widely prescribed diet pills may suffer irreversible loss of brain serotonin nerve terminals, possibly resulting in symptoms of anxiety, depression, cognitive and sleep problems, suggests the first author of a newly published report on fenfluramine side effects. National Institute of Mental Health researcher Una McCann, M.D., and colleagues, report on their review of 90 animal studies on serotonin neurotoxicity and primary pulmonary hypertension from fenfluramine and its chemical cousin dexfenfluramine, in the August 27 issue of the Journal of the American Medical Association.

An estimated 50 million people have taken the drugs, often in combination with phentermine (hence "fen/phen"), an amphetamine-like diet drug that counteracts the fenfluramines' tendency to induce drowsiness. The study cautions that if the animal findings apply to humans, the brain damage "would be expected to occur in almost everyone taking a dose sufficient to achieve weight loss."

"I think there is cause for concern that people who take fenfluramines are at risk for a host of problems," said McCann, chief of anxiety disorders research in the NIMH Biological Psychiatry Branch, Bethesda, MD. "A dose comparable to that prescribed to reduce weight in humans causes neurotoxicity in monkeys."

"It might be justifiable for someone who is morbidly obese and hence at risk for serious health problems, but not for a person who just wants to lose a few pounds for cosmetic reasons," explained McCann. "Many people who try diet pills quickly regain their weight after they stop taking the drugs, so they might be tempted to continue taking them. We won't know the long-term risks of these drugs until controlled studies are completed in humans."

In one study reviewed, monkeys' brains continued to show signs of damage 17 months after taking a course of the drug. Much like the branches of a tree, neurons contain extensions called axons that transport messenger chemicals like serotonin and form synapses -- connections with other neurons. Fenfluramines damage serotonin-secreting neurons by pruning these axons, which do not grow back in monkeys, although studies show that they do in rodents. And since human brains are more like those of monkeys, any such damage in humans would also likely be permanent, according to McCann.

"However, the neurotoxic potential of fenfluramines in humans has not been systematically evaluated," write the researchers. Moreover, "the functional consequences of brain serotonin neurotoxicity are largely unknown," even though the neurotransmitter is thought to be important "in a variety of brain functions, including cognition and memory and the regulation of mood, anxiety, impulsivity, aggression, sleep and neuroendocrine function."

In fact, McCann cites case reports that some users have experienced psychiatric disorders, which, she points out, tend to be under-diagnosed in clinical practice. Studies also document that fenfluramines increase the risk for developing primary pulmonary hypertension, a rare, but incurable and life threatening illness.

The researchers advise doctors to be vigilant for both behavioral and cardiopulmonary side effects, and that patients be apprised of the risks and benefits of fenfluramines for weight loss.

Also participating in the study were: Lewis Seiden, Ph.D., University of Chicago; Lewis Rubin, M.D., University of Maryland; George Ricaurte, M.D., Ph.D., Johns Hopkins University. The study was supported by the NIMH Intramural Research Program and grants from the National Institute on Drug Abuse (NIDA).

NIMH and NIDA are components of the National Institutes of Health, an agency of the U.S. Department of Health and Human Services.


Story Source:

The above story is based on materials provided by National Institute Of Mental Health. Note: Materials may be edited for content and length.


Cite This Page:

National Institute Of Mental Health. "Psychiatric Symptoms May Signal Brain Damage From Diet Pills." ScienceDaily. ScienceDaily, 28 August 1997. <www.sciencedaily.com/releases/1997/08/970828000915.htm>.
National Institute Of Mental Health. (1997, August 28). Psychiatric Symptoms May Signal Brain Damage From Diet Pills. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/1997/08/970828000915.htm
National Institute Of Mental Health. "Psychiatric Symptoms May Signal Brain Damage From Diet Pills." ScienceDaily. www.sciencedaily.com/releases/1997/08/970828000915.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Ebola Virus Threatens West Africa

Deadly Ebola Virus Threatens West Africa

AP (July 28, 2014) West African nations and international health organizations are working to contain the largest Ebola outbreak in history. It's one of the deadliest diseases known to man, but the CDC says it's unlikely to spread in the U.S. (July 28) Video provided by AP
Powered by NewsLook.com
$15B Deal on Vets' Health Care Reached

$15B Deal on Vets' Health Care Reached

AP (July 28, 2014) A bipartisan deal to improve veterans health care would authorize at least $15 billion in emergency spending to fix a veterans program scandalized by long patient wait times and falsified records. (July 28) Video provided by AP
Powered by NewsLook.com
Two Americans Contract Ebola in Liberia

Two Americans Contract Ebola in Liberia

Reuters - US Online Video (July 28, 2014) Two American aid workers in Liberia test positive for Ebola while working to combat the deadliest outbreak of the virus ever. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins