A large number of patients with depression who showed no response to tricyclic antidepressants within three months switched to an SSRI drug,and many of them showed benefits within the next three months.Why is it difficult to draw any conclusion from this result?

Question

A large number of patients with depression who showed no response to tricyclic antidepressants within three months switched to an SSRI drug,and many of them showed benefits within the next three months.Why is it difficult to draw any conclusion from this result?​

Quizplus · Accepted Answer

Without a control group that stayed on one drug for six months or no drug for six months, it is difficult to determine whether the improvement is due to the switch to the SSRI or simply the passing of time or placebo effect. Three months may also not be long enough to fully evaluate the effectiveness of antidepressants. Varying doses and types of drugs may also provide more information, but this is not the main issue with the study. Testing the drugs on people without depression would not be relevant to evaluating the effectiveness of the drugs for depression.

A Large Number of Patients with Depression Who Showed No