Chances are you've taken or come across a personality test. Ranging from quick online tests that describe your personality based on your favorite color or animal, or popular tests such as the Enneagram, Big 5, Socionics or MBTI - generally these tests ask questions that measure your preferences on several dimensions and spit out a contrived archetype. Despite the many differences in these tests, one dimension that appears salient is the scale between extroversion and introversion.
Many take comfort in the term 'introvert' as it describes their preference to turn their attention inward towards their interests and feelings versus their extroverted counter-types whom typically hold their attention outside of their selves. Often times however, introverts get confused with adjectives like shy, aloof or at the worst of all - anti-social. The difference between an introvert and these adjectives is that the introvert has a preference for minimally stimulating environments and activities, where as someone that is shy actually fears social interaction. In other words, the introvert can have no problem going to parties, hanging out in large groups or initiating a conversation with a stranger - they just need their time afterward to recharge after prolonged social interaction. This is not to say that the terms are mutually-exclusive, one can be both introverted and shy, however it is important to discern between the terms.
Like many things in life - balance is key, and too much of anything can be maladaptive. The paradox of the introvert is that they may want to be alone, but don't want to be lonely. How then is the introvert able to cater to themselves without losing touch with the social skills that are necessary to build strong relationships? Introverts focus their energy within themselves, and for this reason they often are finely tuned to their inner-world. At times however, this insight can turn against them and result in feeling stuck within their own mind. This unhealthy expression of the introvert can often begin to snowball in to isolation, over-thinking, depression or social-anxiety.
Therapy can be an effective tool for those of us that have become so immersed in ourselves that we have disconnected from the rest of the world. Using the natural insight that introverts tend to display, therapy can help bring those thoughts and feelings back in to the world. Although many self-described introverts that I have had the pleasure of working with have had very rich inner-worlds, they often have become troubled due to a rigid diet of isolated activities. Therapies such as Rational-Emotive Behavioral Therapy can be a useful way of challenging maladaptive beliefs about the world or the self through examining the inter-play between our thoughts, feelings and the world around us.