Look out for treatment effects that are described as average differences.
Sometimes in treatment comparisons an outcome, like depression or anxiety, is measured on a scale. When scales are used, studies usually report the average difference between the outcome in the treatment group and in the comparison group. But not everyone experiences the average effect. For example, some people may experience a big reduction in anxiety while others may experience no reduction.
REMEMBER: Don’t be tricked by average effects. When outcomes are measured using scales, don’t assume that everyone experiences the average effect.