Lipitor (atorvastatin) is a medication that is used to lower cholesterol levels and prevent cardiovascular diseases [1]. According to the Drug Patent Watch, there is no evidence to suggest that Lipitor can decrease antidepressant efficacy [1].

However, a study published in the National Center for Biotechnology Information found that the combination of atorvastatin and certain antidepressants, such as fluoxetine and sertraline, may lead to a higher risk of bleeding events [2]. The study suggests that physicians should monitor patients closely if they are taking both medications simultaneously [2].

Additionally, the Mayo Clinic warns that ginkgo, an herbal supplement, may interact with antidepressants and increase the risk of bleeding [3]. The combination of ginkgo and atorvastatin may also increase the risk of bleeding [3]. Therefore, it is important to consult with a healthcare provider before taking any new medications or supplements, especially if you are already taking antidepressants and/or atorvastatin [2][3].

In conclusion, there is no evidence to suggest that Lipitor can decrease antidepressant efficacy [1]. However, combining atorvastatin with certain antidepressants may increase the risk of bleeding events [2]. Patients should also be cautious when taking ginkgo supplements in combination with antidepressants and/or atorvastatin [3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9827898/
[3] https://www.mayoclinic.org/drugs-supplements-ginkgo/art-20362032