Biological Aging Theories Theories of biological aging need to explain how aging relates to the evolution process. More specifically, if the evolution process has caused organisms to evolve myriad other ways to survive longer and reproduce more, why does aging still exist? As summarized below, aging theories propose three different answers to this question and are based on three different versions of Darwin's survival of the fittest idea. Simple Deterioration Theories - Fundamental Limitations - "Wear and Tear" Many people believe that biological aging is simply the result of universal deteriorative processes such as oxidation, entropy, or wear and tear that cause aging in machinery, exterior paint, and other inanimate objects.
Introduction The acute toxic effects of MDMA are well documented by hundreds of case reports of adverse events in illicit users. Considering how many people use MDMA, serious acute adverse events seem rare.
MDMA appears generally similar to psychostimulants such as methamphetamine with respect to the risks of acute toxicity. With trained personnel, properly screened volunteers, and established protocols for monitoring and treating adverse events, these acute risks appear modest and do not present a strong argument against carefully conducted clinical research with MDMA.
On the other hand, the risks associated with possible long-term brain damage are more difficult to assess. Numerous studies in animals have shown that MDMA can produce long-lasting decreases in brain functions involving the neurotransmitter serotonin.
It is unclear what these changes mean. Lasting behavioral changes in MDMA-exposed animals have been seldom detected and are fairly subtle when they are found. Though limited in scope, studies of ecstasy users present a strong probability that similar serotonergic changes occur in many humans.
Studies comparing ecstasy users and nonusers support an association between modestly-lowered intelligence testing, or cognitive performance tests, and ecstasy use, but clinically significant performance decreases have not been detected.
In other words, there is no increased incidence of clinical complaints or findings. The modest findings in behavioral studies of MDMA neurotoxicity have led some to dismiss concerns about MDMA neurotoxicity as politically-motivated alarmism.
It is commonly pointed out that though fenfluramine and methamphetamine produce similar changes, their status as prescription medications was not affected by this finding. Although fenfluramine was removed from the U.
In 15 years of research on MDMA neurotoxicity, no published studies have investigated whether MDMA exposure can cause significant toxicity that only becomes apparent with aging. This fact must be taken into account when considering the risks and benefits of possible clinical studies.
Perhaps the single most worrisome issue surrounding MDMA neurotoxicity is that there may be significant toxicity associated with serotonergic changes that is currently undetected.
Although millions of people have taken millions of doses of ecstasy, controlled studies of users have not been large enough to detect any but the most common chronic adverse effects. Possible adverse effects such as an increased incidence of affective disorders, like depression, may have gone unnoticed.
Because so little is known about possible long-term clinical implications of MDMA neurotoxicity, we believe it is important to minimize the risks of neurotoxicity in research volunteers.
It is hoped that the information presented here may contribute to assessments of, and perhaps reductions in, the risks associated with MDMA use. This chapter will discuss 1 the nature and meaning of MDMA-induced serotonergic changes; 2 the possible mechanisms of these changes; 3 factors influencing the severity of these changes such as dose, route of administration, species and animal strain, and environment ; and 4 the time course of these changes and recovery.
The latter part of this chapter will focus on the implications of long-term serotonergic changes by discussing 5 the behavioral and functional effects of MDMA-induced serotonergic changes in animals; 6 studies comparing ecstasy users to nonusers including personality, cognitive, and functional comparisons ; 7 available data from clinical studies in which MDMA was administered; and 8 potential strategies for reducing risk to human volunteers.
Limitations of space unfortunately prevent a full discussion of every important paper and aspect of this complex topic. For a broader sense of the range of views on MDMA neurotoxicity, the reader is therefore advised to consult other review articles Boot, ; Burgess, ; Green, ; Hegadoren, ; McKenna; Morgan ; O'Callaghan, ; Seiden, ; Sprague, ; Steele,and the issue of Neuropsychobiology Vol.
In this chapter, drug doses and dosing patterns used in research that produce these long-term serotonergic changes will be referred to as "neurotoxic regimens.
In this chapter, any changes noted at 7 or more days after drug administration will be considered "long-term. The term "neurotoxicity" is more difficult to define. Though no universal definition exists, most definitions are broad enough to encompass both short-term alcohol-induced headaches and the permanent nerve cell loss caused by the drug MPTP.
A more useful approach to the question of whether MDMA is neurotoxic is to describe the nature and mechanisms of the long-term changes it can cause. In this way, it is evident that some neurotoxic MDMA regimens produce both changes in the serotonergic system and acute damage to the brain by free radicals, and thereby cause a loss of nerve cell axons.
This suggests that MDMA neurotoxicity is a type of drug-induced damage, even though the consequences of this damage are unknown.
MDMA does produce long-lasting changes to the serotonergic system at some doses. These long-term changes include decreases in brain concentrations of the neurotransmitter serotonin 5-HT and its metabolite 5-hydroxyindoleacetic acid 5-HIAA.What does “Drug and Substance Abuse” mean?
Most drugs and other chemical substances are helpful when used properly. Unfortunately, the misuse of medications and drugs—both legal and illegal, as well as alcohol and tobacco—is a growing problem in the older population. The Administration for Community Living was created around the fundamental principle that older adults and people with disabilities of all ages should be able to live where they choose, with the people they choose, and with the ability to participate fully in their communities.
The George Mateljan Foundation is a not-for-profit foundation with no commercial interests or advertising. Our mission is to help you eat and cook the healthiest way for optimal health. How much cannabis is too much for those who start smoking as adults? Below is an approximation of this video’s audio content.
To see any graphs, charts, graphics, images, and quotes to which Dr.
Greger may be referring, watch the above video. “Can the recreational use of marijuana cause. Continued. Primary focal hyperhidrosis does not cause illness. Basically, you just sweat excessively. Although it is a medical condition, it's not a sign of disease or a drug feelthefish.com There are multiple ideas to support the idea that an aging population will cause problems to society.
One point is the cost of the NHS is going to rapidly increase. The Griffiths Report () supports this statement because it presented that as the number of old people increases so does the cost of health and social care.
Therefore if there is.