Time to get high- Circadian rhythms and drug use

Contributing Co-Author: Andrew Chen

Like most living creatures, humans have internal biological clocks known as circadian rhythms. These internal cycles synchronize our bodies with the Earth’s 24-hour day/night cycle and prepare us for predictable daily events (1). Circadian rhythms regulate a number of bodily functions including temperature, hormone secretion, bowel movements, and sleep (2). Recent research suggests that drug use may disturb our circadian rhythms, possibly influencing our decisions to take drugs.


Environmental drivers of drug use

Our biological clocks are set by external cues from the environment, called zeitgebers (3). The most familiar to us are light and food. However, research on rats has shown that opiates, nicotine, stimulants, and alcohol also have the ability to alter the phase of circadian rhythms independent of light or food (1). Drug use has long been associated with major disruptions in the human sleep cycle. Cocaine, crystal meth, and MDMA users often go without sleep for days, and these sleep disruptions can continue long after people stop using drugs. In fact, sleep disturbance outlasts most withdrawal symptoms and places recovering addicts at greater risk for relapse (3).

The rhythm of drug use

Circadian rhythms could also be the reason why people show 24-hour patterns of drug use. A study of urban hospitals found that overdose victims are admitted to hospitals more around 6:30PM than any other time of the day (2). Fluctuations in drug sensitivity, effect, and reward value are believed to be regulated by genes that control circadian rhythms. In other words, our biological clocks are telling us when to get high.

Researchers are just beginning to explore the relationship between circadian rhythms and drug use. Future understanding of this relationship will help us explain how drug addiction develops and develop better ways to treat it. It’s possible that offering specific aspects of treatment as certain point in the circadian rhythm can improve the probability of success.


1. Kosobud, A. E. K., Gillman, A. G., Leffel, J. K., Pecoraro, N.C., Rebec, G.V., Timberlake, W. (2007) Drugs of abuse can entrain circadian rhythms, The Scientific World Journal, 7(S2), 203-212

2. McClung, C.A. (2007) Circadian rhythms, the mesolimbic dopaminergic circuit, and drug addiction, The Scientific World Journal, 7(S2), 194-202

3. Gordon, H.W. (2007) Sleep, circadian rhythm, and drug abuse, The Scientific World Journal, 7(S2), 191-193

4 responses to “Time to get high- Circadian rhythms and drug use”

  1. It’s a fascinating area. There is no doubt that consumption of alcohol in particular interferes with the body’s biological ability to synchronize its daily activities with light, and research seems to show that people who drink alcohol late at night are probably less likely to respond appropriately to light cues, and therefore less likely to keep their biological clocks synchronized over the next 24 hours.

  2. 6:30 pm – 90 minutes after getting out of work.

    15-30 minutes to get home, 15-30 minutes to get really high, 15-30 minutes to realize there is a major problem, and 15-30 minutes to get to the hospital. On average that would be 90 minutes from getting out of work to landing in the ER.

  3. I know it factors in, just don’t know why. I’ll be interested to learn more, as the research develops the connections.

  4. so what is the opiate relation here? I take 80mg x every 8hrs and wanted to as if the 80mg is really necessary at my pre sleep dose? or???

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