Control Group Design: Enhancing Rigor in Research of Mind-Body Therapies for Depression

Table 3

Considerations about types of control groups in studies of mind-body therapies.

Control groups	Pros	Cons
Usual care control	(i) Ethical	(i) Variability in usual care for depression according to the individual; (ii) Attrition
Wait-list control	(i) Ethical; (ii) Enhance recruitment and retention	(i) Expectation bias; (ii) Does not allow for blinding of participants to hypothesis; (iii) Extends study time; (iv) Waiting too long for intervention may lead to attrition; (v) No control for non-specific treatment effects
Active control	(i) Ethical; (ii) Enhance recruitment and retention; (iii) May allow for blinding of participants to hypothesis; (iv) Control for threats to internal validity	(i) Must exactly parallel treatment group in time and attention; (ii) May become an intervention in and of itself; (iii) May be more difficult to detect treatment effect