PCP Users Were More Violent Toward Partners Than Cannabis or Alcohol Users | Research

The takeaway

Compared to cannabis users and polysubstance (alcohol and cannabis) users, PCP users were significantly more likely to have perpetrated intimate partner violence and had more extensive legal histories.

Read this if you want to understand how different substances relate to violent behavior.

PCP users had higher violence rates than both cannabis and polysubstance groups

What the researchers found

Researchers compared 109 PCP users, 81 cannabis users, and 97 polysubstance (alcohol and cannabis) users from substance abuse evaluations. PCP users were more likely than both comparison groups to have received inpatient referrals, have significant legal histories, and have perpetrated both general violence and intimate partner violence in the past year.

The finding that PCP users were more violent than even polysubstance users (who used both alcohol and cannabis) suggests that PCP has a specific association with violence beyond what can be attributed to general substance use.

Why it matters

Cannabis is often discussed alongside more dangerous drugs, but this study provides context showing that the violence profile of cannabis users is significantly lower than PCP users. The cannabis-only group served as a comparison baseline, helping distinguish substance-specific effects.

The numbers in context

109 PCP users vs. 81 cannabis users vs. 97 polysubstance users. PCP users had higher rates of: inpatient referrals, legal history, past-year general violence, past-year intimate partner violence. All comparisons significant relative to both other groups.

How the study worked

Cross-sectional comparison of substance abuse evaluations from 109 PCP-addicted, 81 cannabis-abusing, and 97 polysubstance (alcohol and cannabis)-abusing offenders. Compared rates of inpatient referral, legal history, general violence, and intimate partner violence.

What this study cannot tell us

Cross-sectional design cannot prove PCP use causes violence. All participants were offenders undergoing substance abuse evaluation, not a general population sample. Selection into PCP use may involve pre-existing traits that also predict violence. The groups may differ on unmeasured variables.

How to read the evidence

Cross-sectional comparison of offender evaluations; preliminary evidence limited by the sample and design.

When this study was published

Published in 2013. The relationship between specific substances and violence continues to be studied.

The bigger picture

This study contributes to the evidence that different substances have very different associations with violence. While cannabis is sometimes lumped together with other illegal drugs in policy discussions, its violence profile is substantially different from drugs like PCP.

Questions still open

What specific properties of PCP contribute to violent behavior? Should violence risk assessment tools incorporate substance-specific information? How do cannabis users' violence rates compare to the general population?

Common questions

Does cannabis cause violence?

This study found that cannabis-only users had significantly lower rates of violence than PCP users. While the study was not designed to determine whether cannabis causes or prevents violence, the cannabis group served as a lower-violence comparison group, suggesting cannabis has a different relationship to aggression than drugs like PCP.

Why is PCP associated with more violence?

PCP (phencyclidine) is a dissociative drug that can cause agitation, paranoia, distorted perception, and impaired judgment. These pharmacological effects may directly contribute to aggressive behavior. In contrast, cannabis tends to produce sedation and reduced aggression in most users.

Read the original research

The association between phencyclidine use and partner violence: an initial examination.

Journal of addictive diseases, 32(2), 150-7

View on PubMed ↗Publisher’s paper ↗

Citation

Crane, Cory A; Easton, Caroline J; Devine, Susan. (2013). The association between phencyclidine use and partner violence: an initial examination.. Journal of addictive diseases, 32(2), 150-7. https://doi.org/10.1080/10550887.2013.797279