The bored antihero became prominent in early 20th century existentialist works such as Franz Kafka's The Metamorphosis (1915),[43] Jean-Paul Sartre's La Nausée (1938) (French for 'Nausea'),[44] and Albert Camus' L'Étranger (1942) (French for 'The Stranger').[45] The protagonist in these works is an indecisive central character who drifts through his life and is marked by ennui, angst, and alienation.[46]
Finally, a real problem caused by boredom is that it leads you to dislike the things that are the object of boredom. In my senior year of high school, for example, I was forced to read Moby Dick. I struggled to get interested in it and spent long hours staring at the pages trying to lose myself in it. To this day, I really do not like Moby Dick. The negative feelings that came with the boredom have stuck to the book.
Lethargy is a state of tiredness, weariness, fatigue, or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to boredom, inadequate sleep, overexertion, overworking, stress, lack of exercise, or a symptom of a disorder. When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, and good nutrition.[21][22]
Absent-mindedness is where a person shows inattentive or forgetful behaviour.[20] Absent-mindedness is a mental condition in which the subject experiences low levels of attention and frequent distraction. Absent-mindedness is not a diagnosed condition but rather a symptom of boredom and sleepiness which people experience in their daily lives. When suffering from absent-mindedness, people tend to show signs of memory lapse and weak recollection of recently occurring events. This can usually be a result of a variety of other conditions often diagnosed by clinicians such as attention deficit hyperactivity disorder and depression. In addition to absent-mindedness leading to an array of consequences affecting daily life, it can have as more severe, long-term problems.
A 1989 study indicated that an individual's impression of boredom may be influenced by the individual's degree of attention, as a higher acoustic level of distraction from the environment correlated with higher reportings of boredom.[32] Boredom has been studied as being related to drug abuse among teens.[33] Boredom has been proposed as a cause of pathological gambling behavior. A study found results consistent with the hypothesis that pathological gamblers seek stimulation to avoid states of boredom and depression.[34] It has been suggested that boredom has an evolutionary basis that encourages humans to seek out new challenges. It may influence human learning and ingenuity.[35]

This kind of boredom is different from the others. Like reactant boredom, it’s also unpleasant, but a person experiencing it has low arousal and a lack of positive or negative feelings–in other words, a feeling of helplessness or depression. Of the high school students sampled in the study, 36% of boredom experiences were of the apathetic kind, which is worrisome given that other studies have shown that boredom, depression, and destructive behaviors are often linked.
When the antiproton was discovered … it sent a wave of ennui through the physics community. Not that its discovery was unimportant, but on the basis of Dirac's theory, everybody expected it. — Roger G. Newton, The Truth of Science, 1997 Chauncey and I were keen enough about our aesthetic solution to the ennui of war to try to proselytize others. He organized discussion groups with the crew; I took volunteers to visit landmarks … — Louis Auchincloss, "Atlantic War," in Authors at Sea, ed. Robert Shenk,  1997 The attendant outside was standing on tennis balls, exercising the soles of her feet, her body swaying back and forth with the ennui of jelly. — Edna O'Brien, New Yorker, 17 June 1991 Thus the days of life are consumed, one by one, without an object beyond the present moment; ever flying from the ennui of that, yet carrying it with us … — Thomas Jefferson, in a letter dated 7 Feb. 1787 Thomas Jefferson: Writings,  1984 the kind of ennui that comes from having too much time on one's hands and too little will to find something productive to do