Based on the information provided, there is no direct evidence that Advil (ibuprofen) can decrease the effectiveness of antidepressants. However, it's important to note that both Advil and antidepressants can cause side effects and interact with other medications [2][3].

Advil is a non-prescription medication used to treat pain, inflammation, and fever [1]. Antidepressants, on the other hand, are prescribed to manage depression and anxiety disorders [2].

While the sources do not provide information on the interaction between Advil and antidepressants, they do mention potential interactions between antidepressants and other medications. For instance, certain antidepressants can interact with other drugs that affect serotonin levels, leading to a serious condition called serotonin syndrome [2].

Moreover, stopping antidepressants abruptly can lead to withdrawal symptoms, known as antidepressant discontinuation syndrome [3]. Therefore, any changes to antidepressant medication should be done under the supervision of a healthcare provider.

In conclusion, while there is no specific information about Advil decreasing the effectiveness of antidepressants, it's always important to consult with a healthcare provider before combining medications, due to the potential for interactions and side effects.

Sources:
[1] <https://www.drugpatentwatch.com/p/tradename/ADVIL>
[2] <https://www.mayoclinic.org/diseases-conditions/depression/in-depth/antidepressants/art-20044970>
[3] <https://my.clevelandclinic.org/health/diseases/25218-antidepressant-discontinuation-syndrome>