A Major 1986 Review Found Cannabis's Greatest Health Concern Was Its Effect on Young Users | Research

The takeaway

A comprehensive pharmacological review concluded that cannabis's primary health concern was its impact on adolescent psychological development, while finding no proven brain damage, limited physical dependence, and manageable risks for most adult users.

Read this if you want to understand what mainstream pharmacology concluded about cannabis health risks in the mid-1980s.

No brain damage, limited physical dependence, and no proven immune or chromosomal effects

What the researchers found

This extensive review examined cannabis health effects across virtually every organ system and population group.

The review's central concern was youth: regular cannabis use might stunt emotional growth in adolescents, though whether the drug caused these effects or whether at-risk youth were drawn to use remained unclear. Evidence for an "amotivational syndrome" was largely anecdotal.

For adults, the picture was more reassuring on several fronts. Brain damage had not been proven. Physical dependence was rare in typical social use patterns. No clinical consequences had been documented from effects on immune response, chromosomes, or cell metabolites. Fears about dangerous accumulation in the body were unfounded.

Risks were identified in specific contexts: chronic smoking caused bronchitis (though emphysema and lung cancer had not been documented), cardiovascular effects were harmful for those with pre-existing heart disease, the drug was likely harmful during pregnancy, and driving impairment seemed obvious but was hard to prove definitively. The review singled out herbicide spraying of marijuana crops as the clearest danger to health.

Why it matters

Published in one of pharmacology's most prestigious journals, this review represented the mainstream scientific consensus on cannabis health effects in the mid-1980s. Its nuanced conclusions, acknowledging both real risks and unfounded fears, stood in contrast to more extreme positions on both sides of the debate.

The numbers in context

No specific numeric data highlighted in the abstract beyond noting that nabilone was the only approved synthetic cannabinoid at the time of publication.

How the study worked

Comprehensive narrative review published in Pharmacological Reviews, covering cannabis effects on the brain, behavior, endocrine system, lungs, cardiovascular system, immune system, reproduction, and driving performance.

What this study cannot tell us

Reflects evidence available through the mid-1980s. Cannabis potency, usage patterns, and the volume of research have all changed dramatically. The review's reassurance about lung effects preceded modern research on the topic.

How to read the evidence

A comprehensive narrative review in a top pharmacology journal. Authoritative for its era but limited by the evidence available in the mid-1980s.

When this study was published

Published in 1986. Four decades of subsequent research have substantially refined understanding of every topic covered.

The bigger picture

This review's conclusion that youth were the population of greatest concern has been largely validated by subsequent research. Its observation that many feared health consequences lacked evidence also held up, though decades of additional research eventually documented some effects (like impaired adolescent brain development) more definitively.

Questions still open

Which of this review's conclusions have been confirmed or overturned by subsequent research? Has the concern about adolescent emotional development been validated with stronger study designs?

Common questions

Did the review find cannabis causes brain damage?

No. As of 1986, brain damage from cannabis had not been proven. Subsequent research has identified subtler effects on adolescent brain development.

What was the biggest health concern?

The impact on young users. The review emphasized that regular drug use during adolescence could stunt emotional growth, though cause versus effect remained unclear.

Read the original research

Health aspects of cannabis.

Pharmacological reviews, 38(1), 1-20

View on PubMed ↗

Citation

Hollister, L E. (1986). Health aspects of cannabis.. Pharmacological reviews, 38(1), 1-20.