Psychopharmacology and mental retardation: a 10 year review (1990-1999).

Heavey et al. (2000) read every psych-medication paper written for people with intellectual disability from 1990-1999.

They looked at how many used control groups, random assignment, and clear behavior targets.

Most studies failed these basic quality checks and simply asked, "Did the drug calm the person?"

The review found most prescriptions were given for "behavior control," not for a clear medical need.

Few studies measured real behavior change; they relied on staff impressions that the person seemed quieter.

Tarrant et al. (2018) later showed that even the best-studied drug, methylphenidate, helps only about half of kids with ID plus ADHD, and side effects are common.

Rojahn et al. (1987) is an example of what L et al. criticized: six adults had their antipsychotic cut in half, but the tiny study had no placebo and found no real change—exactly the weak evidence the review rejects.

Hatton et al. (2005) extended the story: five years after the review, nearly half of inpatients with mild ID still received off-label drugs with poor paperwork, showing the practice continued despite the warning.

Lifshitz et al. (2014) answered the critique by giving four concrete rules—define polypharmacy the same way, use big random samples, and track real behavior—so future studies can avoid the 1990s mess.

If you sit in medication meetings, bring data. Ask for a baseline behavior graph and a clear target before any new drug starts. Use direct observation sheets like those outlined in Ahlborn et al. (2008) instead of vague "he seems calmer" notes. Push the team to trial one change at a time and to write a stop-date on the order. These simple steps replace chemical restraint with evidence-based care and protect your clients from the 1990s mistakes.