What are the causes of maladjustment?

This is a really hard question to answer because "maladjustment" is such a huge category. The cause of a person's maladjustment is dependent on the person's age, circumstances, support systems and temperament. And of course, what is the situation to which the person is adjusting poorly?

Often what gets labeled as a maladjustment is a person (usually a child) having a normal reaction to abnormal circumstances. Bottom line is, this question is unanswerable without the questioner giving more information about the situation. My professional opinion (as a person trained and licensed in a mental health field) is that there is no such thing as maladjustment. Human beings adjust in a variety of different ways to a variety of circumstances, and not all circumstances are good for all people. Maladjustment is a label - usually given by non-professionals in schools or institutional settings - to an individual whose manner of adjusting to a situation he or she has been placed in is inconvenient for that school or institution.

If you want to learn about maladjustment, I suggest you look into learning about family systems, or systems theory, in psychology texts or online. Systems theory offers an understandable way to think about how individuals work together when they form a system, as in a family or larger institution.