16.1: Amphetamines and the Brain

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This is a final project completed by Jordan Baur for Chemistry 150 in Spring 2020 at Modesto Junior College. When citing this project, he is the author.

For the final project I have decided to choose to focus on the effects of amphetamines on the brain. The reason for this is that I live in Modesto and there is a lot of drug abuse of methamphetamines and also in college I am increasingly surprised by the amount of people prescribed to and using variations of the same stimulant like Adderall, also a lot of people use it for off label purposes or even without a prescription. With more people being prescribed this drug, the risk of improper use and Adderall addiction has increased. Adderall is a combination drug made from amphetamine, which is the parent drug of methamphetamine. I would like to explore the effect of amphetamines on the brain.

Amphetamine is indicated for the treatment of attention-deficit/hyperactivity disorders (ADHD) as well as for the treatment of central nervous system disorders such as narcolepsy. (1) Amphetamine is also used off-label for the treatment of obesity, depression and chronic pain. (1)

Comparison of structure of amphetamine to other neurotransmitters, showing similar chemical structure

 Figure \(\PageIndex{1}\): Comparison of Amphetamine and other neurotransmitter structures (Sanchez-Ramos, 2004, p. 133).

I have inserted a picture of the chemical structure of amphetamine, methamphetamine various other neurotransmitters to show the similarities in structures (Sanchez-Ramos, 2004, p. 133). In biology structure determines function. But also, simple changes in structure like the presence of a methyl group or a hydroxyl group, can have a huge impact on the effects on the body.

Because of the similarity in structure seen above, amphetamines bind to the receptor protein in the synapse for monoamines(dopamine, norepinephrine and adrenaline) and then are taken into the neuron via these transporter protein receptor. Amphetamines then disrupt the storage of these monoamines in the neuron. This leads to higher amounts of monoamines in the neuron. Then through mechanisms not fully understood, amphetamines then cause the monoamine transporter proteins to run in reverse. There is an increase release of monoamines from the same neuron that took up the amphetamine. This leads to very high levels of this neurotransmitters in the synaptic cleft. This is the basis of the action of amphetamines.

This drug affects reward centers and have a high rate of dependency and abuse. Amphetamine induced psychologic dependence which is manifested by elevated mood, increased wakefulness, concentration, physical performance and a feeling of well-being. With sustained use, the effects of rapid heartbeat and enhanced alertness diminish while adverse effects such as hallucinations and delusions may occur. (1)

It is shown that because of its effects as a stimulant (like cocaine) Adderall and other such amphetamines, do increase mood , attention , focus and maybe even motivation (reward centers). But these effects fail to lead to better performance on a variety of neurocognitive tasks that measure short-term memory, reading comprehension and fluency. This shows that not only does it not benefit students academically but also may impair their performance. It will keep you awake and focused, but sleep is essential to overall health. Also attention and focus is something that can be improved upon over time. The drug however does improve mood but does so by flooding your synapses with neurotransmitters like dopamine. Users often fail to differentiate between how they feel on the drug vs their performance. If you are less miserable when trying to accomplish tasks, you then automatically think you are performing better.

Referring back to the picture with the structures. If you compare amphetamine to methamphetamine, meth has an extra group of carbon with 3 hydrogens ( methyl group). This simple change in chemical structure makes the drug much more addictive and dangerous for use.

Learning Questions :

Why is methamphetamine more dangerous than Adderall?
How does a receptor on a synapse work? Based on shape, chemical composition etc ?
How does a substance that effects the nervous system, end up having an effect on the cardiovascular system ? ( eg Adderall, increased heart rate)

References :

1- “Amphetamine.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, pubchem.ncbi.nlm.nih.gov/compound/Amphetamine#section=Pharmacology-and-Biochemistry.

2- Berman, S M, et al. “Potential Adverse Effects of Amphetamine Treatment on Brain and Behavior: a Review.” Molecular Psychiatry, U.S. National Library of Medicine, Feb. 2009, www.ncbi.nlm.nih.gov/pmc/articles/PMC2670101/.

3- Pedersen, Traci. “Study: Adderall Fails to Boost Cognition in Healthy College Students.” Psych Central, 24 July 2018, psychcentral.com/news/2018/07/24/study-adderall-fails-to-boost-cognition-in-healthy-college-students/137238.html.

4- Reflections Recovery Center. “Adderall Vs Meth - Is Adderall the Legal Version of Meth?” Reflections Recovery Center, 22 July 2019, reflectionsrehab.com/blog/is-adderall-the-legal-version-of-meth/.

5- Sanchez-Ramos, Juan. (2004). Stimulant-induced movement disorders. Drug-induced movement disorders.. 295-308.