Current Neuropharmacology - Volume 13, Issue 1, 2015

Cognitive enhancement can be defined as the use of drugs and/or other means with the aim to improve the cognitive functions of healthy subjects in particular memory, attention, creativity and intelligence in the absence of any medical indication. Currently, it represents one of the most debated topics in the neuroscience community. Human beings always wanted to use substances to improve their cognitive functions, from the use of hallucinogens in ancient civilizations in an attempt to allow them to better communicate with their gods, to the widespread use of caffeine under various forms (energy drinks, tablets, etc.), to the more recent development of drugs such as stimulants and glutamate activators. In the last ten years, increasing attention has been given to the use of cognitive enhancers, but up to now there is still only a limited amount of information concerning the use, effect and functioning of cognitive enhancement in daily life on healthy subjects. The first aim of this paper was to review current trends in the misuse of smart drugs (also known as Nootropics) presently available on the market focusing in detail on methylphenidate, trying to evaluate the potential risk in healthy individuals, especially teenagers and young adults. Moreover, the authors have explored the issue of cognitive enhancement compared to the use of Anabolic Androgenic Steroids (AAS) in sports. Finally, a brief overview of the ethical considerations surrounding human enhancement has been examined.

New psychoactive substances (NPS) have completely modified the drug scene and the current landscape of addiction. Synthetic substances, such as substituted or synthetic cathinones, also known as « legal highs », are often produced and used to mimic the effects of controlled drugs such as cocaine, methylenedioxymethamphetamine (MDMA, ecstasy), and methamphetamine. The overwhelming majority of synthetic cathinones are produced in China and South East Asian countries. The Internet has emerged as the new marketplace for NPS, playing a major role in providing information on acquisition, synthesis, extraction, identification, and substance use. All these compounds are intentionally mislabeled and sold on-line under slang terms such as bath salts, plant food, plant feeders and research chemicals. They are sometimes labeled « not for human use » or « not tested for hazards or toxicity ». The rapid spread of NPS forces member countries of the European Union to adapt their response to the potential new dangers that may cause. To date, not only health actors but also the general public need to be clearly informed and aware of dangers resulting from NPS spread and use. Here, we review the major clinical effects of synthetic cathinones to highlight their impact on public health. A literature search was conducted from 2009 to 2014 based on PubMed, Google Scholar, Erowid, and governmental websites, using the following keywords alone or in combination: “new psychoactive substances”, “synthetic cathinones”, “substituted cathinones”, “mephedrone”, “methylone”, “MDPV”, “4-MEC”, “addiction”, and “substance use disorder”.

Synthetic cathinones are designer drugs of the phenethylamine class, structurally and pharmacologically similar to amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), cathinone and other related substances. New analogues, legal at least, until formally banned (a time consuming process), are introduced almost daily The United Nations estimates nearly 250 new drug analogues are produced per year. Various combinations of these drugs are sold under the name of “bath salts.” They can be ingested by any route and some appear capable of causing great harm, mostly behavioral. One drug in particular, MDVP, appears to frequently cause symptoms indistinguishable from the classic findings in Excited Delirium Syndrome (ExDS). Little is known about the pathology or clinical toxicology of these drugs but their molecular mechanism of action seems to be identical with that of cocaine. This mini-review examines what little is known on the subject and explains the suspected mechanisms of excited delirium syndrome.

The definition New psychoactive substances (NPS) refers to emerging drugs whose chemical structures are similar to other psychoactive compounds but not identical, representing a “legal” alternative to internationally controlled drugs. There are many categories of NPS, such as synthetic cannabinoids, synthetic cathinones, phenylethylamines, piperazines, ketamine derivatives and tryptamines. Tryptamines are naturally occurring compounds, which can derive from the amino acid tryptophan by several biosynthetic pathways: their structure is a combination of a benzene ring and a pyrrole ring, with the addition of a 2-carbon side chain. Tryptamines include serotonin and melatonin as well as other compounds known for their hallucinogenic properties, such as psilocybin in ‘Magic mushrooms’ and dimethyltryptamine (DMT) in Ayahuasca brews. Aim: To review the scientific literature regarding tryptamines and their derivatives, providing a summary of all the available information about the structure of these compounds, their effects in relationship with the routes of administration, their pharmacology and toxicity, including articles reporting cases of death related to intake of these substances. Methods: A comprehensive review of the published scientific literature was performed, using also non peer-reviewed information sources, such as books, government publications and drug user web fora. Conclusions: Information from Internet and from published scientific literature, organized in the way we proposed in this review, provides an effective tool for specialists facing the emerging NPS threat to public health and public security, including the personnel working in Emergency Department.

The illicit recreational drug of abuse, γ-hydroxybutyrate (GHB) is a potent central nervous system depressant and is often encountered during forensic investigations of living and deceased persons. The sodium salt of GHB is registered as a therapeutic agent (Xyrem®), approved in some countries for the treatment of narcolepsy-associated cataplexy and (Alcover®) is an adjuvant medication for detoxification and withdrawal in alcoholics. Trace amounts of GHB are produced endogenously (0.5-1.0 mg/L) in various tissues, including the brain, where it functions as both a precursor and a metabolite of the major inhibitory neurotransmitter γ-aminobutyric acid (GABA). Available information indicates that GHB serves as a neurotransmitter or neuromodulator in the GABAergic system, especially via binding to the GABA-B receptor subtype. Although GHB is listed as a controlled substance in many countries abuse still continues, owing to the availability of precursor drugs, γ -butyrolactone (GBL) and 1,4-butanediol (BD), which are not regulated. After ingestion both GBL and BD are rapidly converted into GHB (t½ ∼1 min). The Cmax occurs after 20-40 min and GHB is then eliminated from plasma with a half-life of 30-50 min. Only about 1-5% of the dose of GHB is recoverable in urine and the window of detection is relatively short (3-10 h). This calls for expeditious sampling when evidence of drug use and/or abuse is required in forensic casework. The recreational dose of GHB is not easy to estimate and a concentration in plasma of ∼100 mg/L produces euphoria and disinhibition, whereas 500 mg/L might cause death from cardiorespiratory depression. Effective antidotes to reverse the sedative and intoxicating effects of GHB do not exist. The poisoned patients require supportive care, vital signs should be monitored and the airways kept clear in case of emesis. After prolonged regular use of GHB tolerance and dependence develop and abrupt cessation of drug use leads to unpleasant withdrawal symptoms. There is no evidence-based protocol available to deal with GHB withdrawal, apart from administering benzodiazepines.

Caffeine use is increasing worldwide. The underlying motivations are mainly concentration and memory enhancement and physical performance improvement. Coffee and caffeine-containing products affect the cardiovascular system, with their positive inotropic and chronotropic effects, and the central nervous system, with their locomotor activity stimulation and anxiogenic-like effects. Thus, it is of interest to examine whether these effects could be detrimental for health. Furthermore, caffeine abuse and dependence are becoming more and more common and can lead to caffeine intoxication, which puts individuals at risk for premature and unnatural death. The present review summarizes the main findings concerning caffeine’s mechanisms of action (focusing on adenosine antagonism, intracellular calcium mobilization, and phosphodiesterases inhibition), use, abuse, dependence, intoxication, and lethal effects. It also suggests that the concepts of toxic and lethal doses are relative, since doses below the toxic and/or lethal range may play a causal role in intoxication or death. This could be due to caffeine’s interaction with other substances or to the individuals&apos preexisting metabolism alterations or diseases.be due to caffeine’s interaction with other substances or to individuals’ pre-existing diseases or metabolism alterations.

Anabolic androgenic steroids (AAS) are some of the most common performance enhancing drugs (PED) among society. Despite the broad spectrum of adverse effects and legal consequences, AAS are illicitly marketed and distributed in many countries. To circumvent existing laws, the chemical structure of AAS is modified and these designer steroids are sold as nutritional supplements mainly over the Internet. Several side effects are linked with AAS abuse. Only little is known about the pharmacological effects and metabolism of unapproved steroids due to the absence of clinical studies. The large number of designer steroid findings in dietary supplements and the detection of new compounds combined with legal loopholes for their distribution in many countries show that stricter regulations and better information policy are needed.

The use of anabolic-androgenic steroids (AASs) by professional and recreational athletes is increasing worldwide. The underlying motivations are mainly performance enhancement and body image improvement. AAS abuse and dependence, which are specifically classified and coded by the DSM-5, are not uncommon. AAS-using athletes are frequently present with psychiatric symptoms and disorders, mainly somatoform and eating, but also mood, and schizophrenia-related disorders. Some psychiatric disorders are typical of athletes, like muscle dysmorphia. This raises the issue of whether AAS use causes these disorders in athletes, by determining neuroadaptive changes in the reward neural circuit or by exacerbating stress vulnerability, or rather these are athletes with premorbid abnormal personalities or a history of psychiatric disorders who are attracted to AAS use, prompted by the desire to improve their appearance and control their weights. This may predispose to eating disorders, but AASs also show mood destabilizing effects, with longterm use inducing depression and short-term hypomania; withdrawal/discontinuation may be accompanied by depression. The effects of AASs on anxiety behavior are unclear and studies are inconsistent. AASs are also linked to psychotic behavior. The psychological characteristics that could prompt athletes to use AASs have not been elucidated.

Nandrolone is included in the class II of anabolic androgenic steroids (AAS) which is composed of 19-nor-testosterone-derivates. In general, AAS is a broad and rapidly increasing group of synthetic androgens used both clinically and illicitly. AAS in general and nandrolone decanoate (ND) in particular have been associated with several behavioral disorders. The purpose of this review is to summarize the literature concerning studies dealing with ND exposure on animal models, mostly rats that mimic human abuse systems (i.e. supraphysiological doses). We have focused in particular on researches that have investigated how ND alters the function and expression of neuronal signaling molecules that underlie behavior, anxiety, aggression, learning and memory, reproductive behaviors, locomotion and reward.

Anabolic-androgenic steroids (AAS) are synthetic substances derived from testosterone that are largely employed due to their trophic effect on muscle tissue of athletes at all levels. Since a great number of organs and systems are a target of AAS, their adverse effects are primarily on the following systems: reproductive, hepatic, musculoskeletal, endocrine, renal, immunological, infectious, cardiovascular, cerebrovascular, and hematological. Neuropsychiatric and behavioral effects as a result of AAS abuse are well known and described in the literature. Mounting evidence exists suggesting that in addition to psychiatric and behavioral effects, non-medical use of AAS carries neurodegenerative potential. Although, the nature of this association remains largely unexplored, recent animal studies have shown the recurrence of this AAS effect, ranging from neurotrophin unbalance to increased neuronal susceptibility to apoptotic stimuli. Experimental and animal studies strongly suggest that apoptotic mechanisms are at least in part involved in AAS-induced neurotoxicity. Furthermore, a great body of evidence is emerging suggesting that increased susceptibility to cellular oxidative stress could play a pivotal role in the pathogenesis of many neurodegenerative disorders and cognitive impairment. As in other drug-evoked encephalopathies, the key mechanisms involved in AAS – induced neuropathology could represent a target for future neuroprotective strategies. Progress in the understanding of these mechanisms will provide important insights into the complex pathophysiology of AAS-induced neurodegeneration, and will pave the way for forthcoming studies. Supplementary to abandoning the drug abuse that represents the first step in reducing the possibility of irreversible brain damage in AAS abusers, neuroprotective strategies have to be developed and implemented in future.

Anabolic androgenic steroids (AASs) represent a large group of synthetic derivatives of testosterone, produced to maximize anabolic effects and minimize the androgenic ones. AAS can be administered orally, parenterally by intramuscular injection and transdermally. Androgens act by binding to the nuclear androgen receptor (AR) in the cytoplasm and then translocate into the nucleus. This binding results in sequential conformational changes of the receptor affecting the interaction between receptor and protein, and receptor and DNA. Skeletal muscle can be considered as the main target tissue for the anabolic effects of AAS, which are mediated by ARs which after exposure to AASs are up-regulated and their number increases with body building. Therefore, AASs determine an increase in muscle size as a consequence of a dose-dependent hypertrophy resulting in an increase of the cross-sectional areas of both type I and type II muscle fibers and myonuclear domains. Moreover, it has been reported that AASs can increase tolerance to exercise by making the muscles more capable to overload therefore shielding them from muscle fiber damage and improving the level of protein synthesis during recovery. Despite some therapeutic use of AASs, there is also wide abuse among athletes especially bodybuilders in order to improve their performances and to increase muscle growth and lean body mass, taking into account the significant anabolic effects of these drugs. The prolonged misuse and abuse of AASs can determine several adverse effects, some of which may be even fatal especially on the cardiovascular system because they may increase the risk of sudden cardiac death (SCD), myocardial infarction, altered serum lipoproteins, and cardiac hypertrophy. The aim of this review is to focus on deaths related to AAS abuse, trying to evaluate the autoptic, histopathological and toxicological findings in order to investigate the pathophysiological mechanism that underlines this type of death, which is still obscure in several aspects. The review of the literature allowed us to identify 19 fatal cases between 1990 and 2012, in which the autopsy excluded in all cases, extracardiac causes of death.