What increases the risk of overdose?
- By Robert Mauer
- Reviewed by: Dr. Janaka Hanvey, PhD
Overdose risk increases with higher doses, high-potency substances, and combining drugs—especially when multiple central nervous system depressants (such as opioids, alcohol, or benzodiazepines) are used together. Unknown strength or contamination further increases risk by making dosing unpredictable.
Individual factors also matter. Low tolerance, underlying health conditions, and using alone increase the likelihood that an overdose becomes severe or fatal.
High-risk situations include changes in supply, mixing substances, and returning to use after a period of abstinence.
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Sources
National Institute on Drug Abuse (NIDA):
https://nida.nih.gov/research-topics/addiction-science
Centers for Disease Control and Prevention (CDC)
https://www.cdc.gov/overdose/prevention/index.html
National Institutes of Health (NIH):
https://www.ncbi.nlm.nih.gov/books/NBK27946/
Substance Abuse and Mental Health Services Administration (SAMHSA):
https://www.samhsa.gov/substance-use