Substances impact people's emotions, behaviors, and cognitions by interacting with or mimicking neurotransmitters. It is important that counselors have an introductory understanding of physiology, as neurological research has a strong potential to alter conceptual paradigms that drive the ways in which counselors understand and intervene with clients.
Substances including marijuana, cocaine, and many prescription medications work by altering the way that neurons and neurotransmitters function. In the following videos, you will learn the different parts of a neuron, what an action potential is, and how neurons send messages from one neuron to the next. This information is foundational to understanding how substances can alter neurophysiology.
Click here to download a notes page that includes vocabulary definitions as well as an overview of the process of signaling within and between neurons.
Playback problems: This video is available on YouTube at youtu.be/xQ-yLKOJBrs
The transcript for the Introduction to Neurons video is available for download here.
Playback problems: This video is available on YouTube at youtu.be/OZG8M_ldA1M?t=3m19s
Playback problems: This video is available on YouTube at youtu.be/VitFvNvRIIY
For an introduction to neurons and neurotransmitters, read the following article:
Check out this webpage for an overview of some of the neurotransmitters.
Psychoactive substances produce their effects by changing people's neurotransmitter levels. Check out this page on MITs website for a summary of how different substances interact with neurons and neurotransmitters.
The National Institute on Drug Abuse (NIDA) also summarizes how neurotransmitters are impacted by drugs. Check out their webpage.
Read through Froehlich (1997) for a summary of how opioids impact neurotransmitters.
Check out the Mouse Party site from the University of Utah to see how different substances impact mice.
The following article exemplifies the ways in which neuroscience and physiology can impact the way that counselors conceptualize and intervene with clients. As you read through the article, try to lookup terms, such as prefrontal cortex and/or striatum that are not familiar. Many counselors and counselors in training will likely find this article to be information dense and difficult to understand. I encourage you to take your time, and to read through the article multiple times.
Functional Magnetic Resonance Imaging (fMRI) is one type of brain imaging that tracks blood oxygen to make an image showing blood flow in different parts of the brain. The more active a part of the brain is, the more energy it uses, which means more oxygenated blood flows to active areas of the brain. Tracking blood flow in the brain allows researchers to better understand how things like substance use impact brain functioning. Gaps or holes (areas without color) on a fMRI image do not mean that area of the brain is dead, or that a real hole exists in the brain. "Holes" on an fMRI image simply mean that area if the brain is less active. I have not seen any research or credible evidence that using drugs puts holes in a person's brain.
Positron emission tomography (PET) scans are another brain imaging technique that uses radioactive chemicals (isotopes) to map brain activity. PET scans are useful for researchers who seek to understand specific neurotransmitters in the brain. Recall from the video on action potentials that ligands bind with receptor sites on neurons to generate an action potential. Scientists attach radioactive isotopes that are detected by PET scans to specific ligands, so that they can visualize receptor sites. Thus, PET scans provide valuable information, such as which brain regions contain receptors for particular substances.
Brain imaging techniques are sometimes misrepresented in the media. For example, reports that drugs put holes in a person's brain:
A healthy brain is smooth and full, but the addicted brain is so severely atrophied that it resembles Swiss cheese. Neuroscientist and psychiatrist Dr. Daniel Amen says these brains are less active, less healthy, and shriveled in appearance and have an overall toxic look, as if acid had been poured over them. Dr. Amen has found that "cocaine and methamphetamine abuse appear as multiple small holes across the cortical surface...
(Jay & Jay, 2008, p. 24)
Statements such as the above quote are inaccurate and misrepresent brain imaging techniques as well as the ways in which substance use impacts brain functioning. Brain imaging studies demonstrate that taking substances can alter brain functioning, activity, and density, however, drugs do not put holes in someones brain. Drugs do not make a brain resemble Swiss cheese. Drugs do not make a brain appear as though acid were poured on it.
Dr. Daniel Amen is a celebrity psychiatrist who has faced criticism from within the scientific community. You can read about him in this Wired Magazine article.
Brain imaging techniques, including fMRI, PET, SPECT, CAT, and others, are important diagnostic tools. Physical health conditions, such as tumors or traumatic brain injuries (TBIs), sometimes present as mental health disorders. Physicians may use brain imaging to rule out diagnoses such as cancer or TBIs. There are currently not enough data to use brain scans as a diagnostic tool for mental health conditions that are not caused by physical health ailments (e.g., depression, anxiety, PTSD, substance use disorders, etc.). However, in the future, brain scans may become foundational mental health diagnostic tools. To learn more about using brain scans to diagnose mental health concerns, check out this blog from Harvard University.
The following video summarizes how fMRI works:
Playback problems: This video is available on YouTube at youtu.be/DaifOWSKjdA