The forced swim test has poor accuracy for identifying novel antidepressants

Despite the prevalence of treatment-resistant depression, many pharmaceutical companies have abandoned the development of new antidepressants. Experts have attributed this, in part, to the low quality of preclinical tests available in this field, often citing over-reliance on animal behavioral screens, such as the forced swim test (FST). This retrospective review assessed whether compounds tested in the FST by major pharmaceutical companies were shown to have antidepressant effects in humans. Of 109 compounds identified, only 28% had been explored for antidepressant effects in humans. Of these, there were only three for which the FST appeared to positively predict antidepressant efficacy, but none are currently approved to treat any type of depression. With such poor accuracy for identifying novel antidepressants, the FST might not be a useful screening tool for this purpose.

Automated summary

Despite the prevalence of treatment-resistant depression, many pharmaceutical companies have abandoned the development of new antidepressants due to low quality preclinical tests, such as over-reliance on animal behavioral screens like the forced swim test (FST). A retrospective review found that out of 109 compounds tested in the FST, only 28% were explored for antidepressant effects in humans, and only three showed potential efficacy, but are not approved for treating depression. This suggests that the FST may not be a useful screening tool for identifying novel antidepressants.