Theatre of the Absurd was a style of writing that emerged after the end of WWII, when there was a sudden shock and distancing from the ideals. This style is characterized by an exploration of existentialism, or the thought about what the meaning of life is. Black humor is often used to explore feelings of despair and hopelessness.

Samuel Beckett is one of the pioneers of this style, and while we can't know the role his depression played in his writing, there might be a few connections. For example, one of his most famous plays, Waiting for Godot, is filled with emptiness and hopelessness, as well as motifs and themes of suicide. Happy Days, for example, also focuses on themes of living a meaningless existence. However, while most of the themes of his plays seem dark, we must also remember that this hopelessness was an experience that many were having in the post WWII era, and that Beckett was also an excellent writer in weaving in humor with these otherwise dark themes.