Abnormal Psychology: Mental Health and Mental Illness


How do we know that a drug works?

The standard method for testing the efficacy of a new drug is through the use of randomized controlled trials (RCTs). In an RCT, a large sample of patients are randomly assigned to receive either the test treatment or a comparison treatment. The comparison drug may be another active drug or may be a placebo (sham treatment that looks like an active drug). Studies must also be double-blinded, that is neither doctor nor patient should be able to tell whether the patient is taking the drug or the placebo. At the end of a set period, symptom improvement is compared across groups. The efficacy of the drug reflects the improvement of symptoms in patients taking the active treatment, rather than the placebo.


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