Secondly , critics argue that many cases of placebo -induced improvement take place just at a psychological level .
Second , critics argue that many cases of placebo induced improvement that took place only at a psychological level . Secondly , critics argue that many cases of placebo-induced improvements take place just at a psychological level . Secondly , critics argue that many cases of placebo-induced improvement take place at just a psychological level . Secondly , critics argue that many cases of placebo-induced improvement take place just at a psychological level .