This 44th annual review compiles research from 2021 on how endogenous opioid peptides influence pain, addiction, mood, eating, learning, and numerous other behaviors and physiological functions.
18 topic areas reviewedThe 44th annual installment covers all aspects of endogenous opioid peptide research from molecular studies to behavior, spanning 2021 publications
What the researchers found
This review consolidates research from 2021 across 18 major topic areas related to endogenous opioid peptides: molecular/biochemical studies, animal and human pain/analgesia, nonopioid analgesics, tolerance and dependence, stress and social status, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, mental illness and mood, seizures, neurophysiology, locomotion, gastrointestinal/renal/hepatic function, cardiovascular responses, respiration and thermoregulation, and immunological responses.
As a comprehensive anthology, the review does not present a single finding but rather synthesizes the state of the field across all behavioral dimensions of opioid peptide research from a single year.
Why it matters
The endogenous opioid system is central to pain management, addiction, mood regulation, and numerous other physiological processes. This annual review series provides an invaluable consolidated reference that helps researchers track progress across the entire field and identify emerging trends in opioid peptide research.
How the study worked
This is a systematic annual review of published literature from 2021 covering all aspects of endogenous opioid peptide research. The author compiled and organized studies by topic area, covering molecular, pharmacological, and genetic manipulation of opioid peptides and receptors.
What this study cannot tell us
As a review article, this does not present new experimental data. The quality and conclusions depend on the underlying studies reviewed, which vary in rigor. The breadth of coverage (18 topics) means individual studies receive limited detailed analysis. Only studies from 2021 are included.
How to read the evidence
This is a narrative review article that compiles and summarizes existing research. It does not present original data but serves as a valuable reference for the field's progress in a given year.
When this study was published
Published in 2023, this review covers research from 2021. As part of a continuous 44-year annual review series, it provides historical context alongside recent findings.
The bigger picture
Understanding endogenous opioid peptides is crucial for developing better pain treatments, addressing the opioid addiction crisis, and understanding how the brain regulates mood and behavior. This review series, spanning over four decades, provides unique longitudinal perspective on how the field has evolved.
Questions still open
- Which areas of endogenous opioid research showed the most significant advances in 2021?
- How are endogenous opioid peptides being explored as alternatives to synthetic opioids for pain management?
- What new therapeutic targets in the opioid peptide system have emerged from recent research?
Common questions
What are endogenous opioid peptides?
Why is this review published every year?
Read the original research
Endogenous opiates and behavior: 2021.
Peptides, 164, 171004
Citation
Bodnar, Richard J. (2023). Endogenous opiates and behavior: 2021.. Peptides, 164, 171004. https://doi.org/10.1016/j.peptides.2023.171004