Recreational drugs and consent

Sir, having worked as a dental foundation trainee last year, and a dental core trainee this year, I have encountered multiple patients openly admitting to taking recreational drugs.

As we know, the human nervous system is an intricate, elaborate system controlled by the brain. The neurone transmits information onto adjacent neurones, which in turn release neurotransmitters that have different effects depending on the receptors they act upon. Recreational drugs, however, have been proven to disrupt this neurotransmitter system; cocaine and methamphetamine overstimulate receptors leading to acute effects such as increased energy, euphoria and even mental alertness.1 Marijuana has been seen to disrupt attention, memory and cause changes to white and grey matter, affecting brain development.2

I have therefore found valid consent taking much more ambiguous than I imagined. Consent is valid when a patient with capacity understands the treatment proposed, weighs up the risks and benefits, retains the information and can relay this back to the practitioner.3 However, I have had encounters with patients who meet these requirements, while simultaneously admitting to being on recreational drugs at the same visit.

If a patient fulfils all aspects of consent, but admits to not being in a sober mental state, is consent really still valid? Admittedly, when the appointment requires immediate pain relief or emergency aid, the patient's best interest is put first and the answer is clearer. However, the question poses itself: can valid consent be provided for routine treatment of patients who are regularly on recreational drugs?


  1. 1.

    Center for Substance Abuse Treatment. Treatment for Stimulant Use Disorders. Rockville (MD): Substance Abuse and Mental Health Services Administration (US), 1999. (Treatment Improvement Protocol (TIP) Series, No. 33.) Chapter 2 - How Stimulants Affect the Brain and Behavior. Available at: (accessed November 2020).

  2. 2.

    Jacobus J, Tapert S F. Effects of cannabis on the adolescent brain. Curr Pharm Des 2014; 20: 2186-2193.

  3. 3.

    Mental Capacity Act 2005. 1st ed. Section 16A. Available at: (accessed 7 July 2017).

Download references

Author information



Corresponding author

Correspondence to T. El-Roz.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

El-Roz, T. Recreational drugs and consent. Br Dent J 229, 638 (2020).

Download citation


Quick links