Virginia Woolf argues that for Modernist writers "the point of interest lies...in the dark places of psychology." What are some examples of this type of writing and what are its features?

Virginia Woolf battled severe depression throughout most of her adult life, which finally culminated in her suicide in 1941. She contributed to literary theories and believed that modernist writers should be more cerebral. Woolf opined that writing is a form of exorcism, in which the writer taps into the dark and primal parts of their subconsciousness.
In Orlando, Woolf writes, "Nothing thicker than a knife's blade separates happiness from melancholy." Woolf herself was very much aware of the "dark places" of her psychology. The dark place Woolf refers to could be suppressed emotions, like angst and melancholy. A dark place could also be traumas experienced in the past, such as sexual abuse or witnessing the violence of war.
Woolf stated that "all extremes of feeling are allied with madness." Woolf believed that a writer can only reach authenticity when she has confronted the possibility of madness. In a sense, confronting one's potential madness and the intense underlying emotions hidden in the subconscious is a form of liberation via self-discovery.
Another writer who explored the "dark places of psychology" is Sylvia Plath. Her critically-acclaimed novel, The Bell Jar, explored Plath's experiences with bipolar disorder in the form of a narrative. In The Bell Jar, each alternating chapters unintentionally show the phases—mania and melancholia—that Plath was experiencing while writing them.
Fyodor Dostoyevsky also explored the dark side of one's psyche, but in the form of a philosophical inquiry into morality, spirituality, primal violence and guilt. This is best exemplified by his novel, Crime and Punishment.