Also referred as psychostimulants, stimulants are psychoactive drugs that result in temporary improvements in mental and/or physical performance. Thus, these compounds produce a variety of different kinds of desirable effects by enhancing the activity of the central and peripheral nervous systems: enhanced alertness and awareness, wakefulness, endurance, productivity, increased arousal and motivation, and a diminished perception of food and sleep needs. Also, many stimulants have also certain properties that can improve mood and relieve anxiety , eventually inducing feelings of euphoria at moderate clinical doses. Too good to be true?
Indeed. Many stimulants are also capable of causing anxiety, dysthymia, hyperactivity and, potentially, heart failure at high doses since they rise blood pressure and locomotion. But these short-term problems are not the most serious ones (since they require a considerable amount of recklessness): addictionto stimulants can quickly lead to medical, psychiatric, and psychosocial deterioration . Unfortunately, its abuse its common and easy to develop. Drug dependence, tolerance and sensitization, as well as withdrawal symptoms, are the other side of the coin. Every addict has said at some point: “I can manage it”, but the brain does not work exclusively consciously.
Being addicted to stimulants might cause your body to reduce dramatically its production of natural neurotransmitters that fulfill similar functions,the most prominent of which include facilitation of norepinephrine (noradrenaline) and/or dopamine activity, adenosine receptor antagonism, and nicotinic acetylcholine receptor agonism. Thus, until your body reestablishes its normal state (if it does, since there is some studies that suggest that among chronic users the damage might be permanent), you may feel depressed, lethargic, and with a detrimental brain fog . Among certain users, also psychosis has been reported . This is what users call a “crash”, unpleasant state that can provoke a reuse of the compound, which efficacy tend to decrease over time, leaving the user with an imbalanced account of benefits and side-effects .
Typically, stimulants are divided in three differentiated groups according to their effects: ampakines, eugeroics, and ADHD drugs.
Ampakines
1. https://www.ncbi.nlm.nih.gov/pubmed/24790000
2. https://www.ncbi.nlm.nih.gov/pubmed/26070753
3. https://www.ncbi.nlm.nih.gov/pubmed/26070754
4. https://www.ncbi.nlm.nih.gov/pubmed/25601645
5. https://www.ncbi.nlm.nih.gov/pubmed/26070758
Ampakinesinteract strongly with glutamatergic AMPA receptors, enhancingattention span and alertness, and facilitatinglearning and memory. The main advantage of ampakines over the “traditional stimulants” (such amphetamines) is that they lack direct dopaminergic action, so they increase alertness without the peripheral effects of addiction and tolerance .
On the other hand, the main disadvantage of ampakines is that they seem to reduce the quality of sleep (and therefore, affecting memory in the long-term run). While these type of drugs can help reducing the effects of sleep deprivation in the short-term, they impact especiallyslow-wave recovery sleep, which is essential for an adequate cognitive function (idem).
Eugeroics
Eugeroics arewakefulness-promoting agentsthatdecrease tiredness, drowsiness, and diminishes the perception of sleep needs by increasing catecholaminergic (adrenergic, dopaminergic) and histaminergic activity in the brain. They are frequently usedfor sleeping disorders, such as excessive daytime sleepiness or narcolepsy, enhancingmotivation and productivity in a short-term basis . The main advantage of eugeroics is that they do not typically produce the “crash” state associated to other stimulants. Unfortunately, developing tolerance is a frequent complaint when using eugeroics, even though they are relatively non-addictive and non-dependence-forming.
ADHD drugs
The stimulant drugs usually prescribed to treat attention deficit hyperactivity disorder (ADHD) are generally effective and safe in the short term. Most children and teenagers—up to 60-80 percent—who take them decrease their hyperactivity and impulsivity, get better at focusing and concentrating, and hence experiment more success at school. However, the main disadvantage about ADHD drugs is there is no good evidence showing those benefits last for longer than two years , and even though adultswith ADHD also appear to benefit from taking medication, far fewer studies have examined the effectiveness& safety of the medicines in adult men and women . For a more comprehensive review of ADHD drugs, please refer to this article.
6. https://www.ncbi.nlm.nih.gov/pubmed/16890999
7. https://www.ncbi.nlm.nih.gov/pubmed/20358418
8. https://www.ncbi.nlm.nih.gov/pubmed/25617040
9. https://www.ncbi.nlm.nih.gov/pubmed/23216449
In conclusion, while the therapeutic use of stimulants is rather approved and even advertised by doctors in the case of determined conditions such as ADHD and narcolepsy, further research is needed to confirm if these benefits can be applied to healthy adults as well. There are some recent studies that show their efficacy and relative safety in the short term , yet its use in the long-term is rather a mystery. Like many other compounds (but specially in this case, since its prevalent abuse potential), moderation is urged.