There are three types of boredom, all of which involve problems of engagement of attention. These include times when we are prevented from engaging in wanted activity, when we are forced to engage in unwanted activity, or when we are simply unable for some other reason to maintain engagement in an activity.[13] Boredom proneness is a tendency to experience boredom of all types. This is typically assessed by the Boredom Proneness Scale.[14] Recent research has found that boredom proneness is clearly and consistently associated with failures of attention.[15] Boredom and its proneness are both theoretically and empirically linked to depression and similar symptoms.[16][17][18] Nonetheless, boredom proneness has been found to be as strongly correlated with attentional lapses as with depression.[16] Although boredom is often viewed as a trivial and mild irritant, proneness to boredom has been linked to a very diverse range of possible psychological, physical, educational, and social problems.[19]
Boredom also has its benefits. It is important to see boredom as a “call to action” (Svendsen, 1999). Nietzsche suggested that men of rare sensibility value boredom as an impetus to achievement. Boredom can be a catalyst for action. It can provide an opportunity for thought and reflection. It can also be a sign that a task is a waste of time—and thus not worth continuing.
“Boredom – the psychological state that we experience whenever we are uninterested in what we are currently doing – is one of the defining traits of humanity. Time is the psychological nemesis of humankind. Tedium, a fundamental angst of humankind, arises from human beings’ ability to perceive time and our attempts to derive meaning from our personal existence.”

Boredom also plays a role in existentialist thought. Søren Kierkegaard and Friedrich Nietzsche were two of the first philosophers considered fundamental to the existentialist movement. Like Pascal, they were interested in people's quiet struggle with the apparent meaninglessness of life and the use of diversion to escape from boredom. Kierkegaard's Either/Or describes the rotation method, a method used by higher level aesthetes in order to avoid boredom. The method is an essential hedonistic aspect of the aesthetic way of life. For the aesthete, one constantly changes what one is doing in order to maximize the enjoyment and pleasure derived from each activity.
“Boredom is a flight from what is important. Like workaholism and perfectionism, it is a way of distracting yourself from inner experiences. It occurs when you look outward and do not find anything to engage your attention. Instead of feeling your emotions - becoming aware of the functioning of your energy system - you become bored. Boredom ... is a flight from your higher potential. It is fear of the transformation that wants to occur, and will occur in you, when you explore your emotions. It is your resistance to spiritual growth.”
The authors of this paper point to an interesting study by Robin Damrad-Frye and James Laird in the August 1989 issue of the Journal of Personality and Social Psychology. In this study, participants had to listen to a tape of a person reading a Psychology Today article. In the next room, there was a television soundtrack from a soap opera playing. For some groups listening to the article, the TV was very loud and distracting, for others it was barely noticeable, and for some it was not playing at all. After listening to the article, people rated their boredom during the study. 
“I asked myself whether a life devoid of any affection, of any goal, a life one fills with a thousand trifles intended to relieve its monotony, populated with human beings one seeks out in order not to be alone and whom one flees to avoid being bored by them, whether such a life isn't ridiculous, whether anything whatsoever wouldn't be preferable.”
Second, boredom typically occurs when people have trouble focusing their attention and they believe the reason for this difficulty is in the environment. When sitting in the airport, for example, there is probably a lot going on. There are people having conversations that you could listen to. You probably have something to read. There may be televisions showing the news. But, the stress of waiting for a delayed flight often makes it hard to concentrate, and so your mind jumps from one thing to another. You assume that this is caused by the environment, and so you feel boredom.
Some individuals are more likely to be bored than others. People with a strong need for novelty, excitement, and variety are at risk of boredom. These sensation seekers (e.g., skydivers) are likely to find that the world moves too slowly. The need for external stimulation may explain why extroverts tend to be particularly prone to boredom. Novelty seeking and risk-taking is the way that these people self-medicate to cure their boredom.