Jul 22, 2020
Dmitry M. Arbuck, MD, joins host Lorenzo Norris, MD, to discuss
ways psychiatrists can help patients with treatment-resistant
Arbuck is clinical assistant professor of psychiatry and
medicine at Indiana University, Indianapolis. Dr. Arbuck also
serves as president and medical director of Indiana Polyclinic, a
multispecialty pain management facility, and is an associate editor
of Current Psychiatry.
Both Dr. Arbuck and Dr.
Norris disclosed having no conflicts of interest.
And do not miss the “Dr. RK” segment, where Renee Kohanski, MD, discusses part 2
of her examination of the constructs of medicine.
- Acute and chronic pain are mediated by different mechanisms and
therefore must be treated differently. Acute pain is caused by
tissue damage leading to nociception, and it should heal. Chronic
pain is the chronification of acute pain and more of an emotional
state with sensations of pain without clear tissue damage.
- Many neurotransmitters are involved in pain, including
dopamine, serotonin, norepinephrine, and the opioid system.
- The levels of neurotransmitters will change as the pain
(emotional and physical) thresholds change.
- When patients with borderline personality disorder cut
themselves, dopamine increases, and the patients, in turn, feel
better. Likewise, when patients with PTSD reexperience negative
events, this causes an increase in dopamine to protect against
- Psychiatrists are particularly well positioned to help those
with chronic pain because trauma and emotions are central to the
perception of emotional and physical pain. Emotional trauma also
influences the severity and chronicity of pain.
- Currently, pharmacogenetics are more of a general guide for
clinicians than specific practice guidelines. But they can inform
patients and physicians about drug metabolism and expression of
receptors in difficult-to-treat patients.
- Chronic pain can be understood as emotions colored by
nociception, while acute pain is the tissue damage and subsequent
nociception causing pain. Opioids suppress the nociception of pain
and are appropriate in acute pain. However, opioids should be used
only in the normal time of healing in acute pain. If their use is
extended, opioids can cause hyperalgesia, thus worsening chronic
- Many forms of chronic pain, such as fibromyalgia and chronic
back pain, do not have tissue damage. The sensations of physical
pain and the compounding emotional pain are mediated by central
pain sensitization. The theory behind central pain sensitization
helps explain why medications such as SSRIs,
serotonin-norepinephrine reuptake inhibitors, and antipsychotics
can come into play in chronic pain treatment.
- In some patients, there can be dopaminergic hyperactivity in
chronic pain. Dr. Arbuck conceptualizes dopamine as a defensive
neurotransmitter. Dopamine is secreted in response to fear and can
result in a physical response, such as weakness in the legs, but it
also leads to emotional consequences, such as dissociation.
Dopamine is also secreted with emotionally painful stimuli, such as
trauma, so an event such as a sexual assault that results in a
physical and emotional injury may produce substantial dopamine
secretion. When the defense becomes chronic, excessive dopamine
secretion can be pathological.
- Pharmacogenetics inform clinicians about a patient’s ability to
benefit from medications by looking at the presence of specific
alleles for enzymes that metabolize medications and for receptors
upon which medications act. Currently, Dr. Arbuck uses
pharmacogenetics in specific indications, such as for patients with
a seemingly treatment-resistant condition or with excessive adverse
effects from medications.
- The pharmacogenetics results are meant to help physicians and
patients understand the body’s role in medications.
- Psychiatry needs to look more into the medical aspects of
mental health, and training in psychiatry needs to be more
biological in nature.
Current Psychiatry. 2020 Jan;19(1):25-9;31.
Clauw DJ. JAMA.
Nijs J et al.
Expert Opin Pharmacother. 2014 Aug;15(12):1671-83.
Dale R and Stacey B.
Med Clin North Am. 2016 Jan;100(1):55-64.
Show notes by Jacqueline Posada, MD, who is associate producer
of the Psychcast and consultation-liaison psychiatry fellow with
the Inova Fairfax Hospital/George Washington University program in
Falls Church, Va. Dr. Posada has no conflicts of interest.
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