To which movements can we relate Heart of Darkness?It would be great if the answer addressed movements such as impressionism, realism, etc.

In terms of literary movements, Heart of
Darkness is often cited as a transition into modern realism. First appearing
in print in 1899 as a magazine serial, it was then published in novel form in 1902 as
part of a collection of Conrad's work. It has been referred to as a novel that acts as a
bridge between the Romantic literature of the 19th Century and the modern realism of the
20th Century. In its stark depiction of the stupidity, cruelty, and greed of colonial
policies inflicted upon native populations, the novel creates a narrative of realistic,
often shocking detail. It focuses upon the inner life of its protagonist, Charlie
Marlow, but not in the manner associated with Romanticism; instead it explores Marlow
(and his antagonist Kurtz) in terms of the human psyche. The influence of Sigmund
Freud's revolutionary modern theories of the unconscious self is readily apparent in the
novel. Other literary techniques, such as the complex structure and point of view, moved
the novel into the realm of modern realism and foreshadowed the work of important 20th
Century writers that followed.