Reading focus
Syllabus: How Can Couples, Families and Groups Become Settings for Change?
Separate evidence of a peer process from evidence that treatment causes worse outcomes.
Why you’re reading it. Apply the same standards to warnings as to claims of benefit, without dismissing harms hidden by averages.
A question to consider. Design a comparison that could reveal delayed harm for some members even when the group improves on average.
Why this reading
Warnings about harm deserve the same scrutiny as promises of benefit. Weiss and colleagues reconsider claims that grouping young people with conduct problems increases those problems, separating a plausible peer process from evidence about treatment effects.
Before you read
Iatrogenic harm is caused by an intervention. Peer reinforcement is a proposed mechanism. Less benefit than another treatment, deterioration over time and harm relative to an appropriate comparison are different claims.
Read for
- Follow the reanalysis of earlier studies and the new meta-analytic comparisons.
- Ask which populations, settings and time periods the available evidence covers.
Consider afterwards
- Could average benefit conceal harm to a subgroup?
- What would a prospective study need to measure to test peer reinforcement as a harmful mechanism?
Editorial context
This historical reappraisal finds little support for a broad claim of harmful group-treatment effects in the studies examined. It does not establish that peer contagion never occurs or that groups are universally safe. Its focus on youth conduct problems should not be generalized to all group psychotherapy.