When individuals experience persistent and uncontrollable thoughts or feel compelled to repeat behaviors again and again, they are likely to be suffering from an obsessive-compulsive disorder. Obsessions are recurring thoughts that cannot be controlled and are so pervasive as to interfere with day-to-day functioning. Some obsessions may appear as extreme worrying or indecision in which the individual debates over and over again, “Should I do this or should I do that?” Compulsions are behaviors that are repeated continually to reduce distress or prevent something terrible from happening. For example, individuals with a compulsion to wash their hands for 20 minutes at a time may believe that this prevents germs and deadly disease. The fear is exaggerated, and the compulsion interferes with day-to-day activity. Individuals with an obsessive-compulsive disorder differ as to whether their symptoms are primarily obsessions, compulsions, or a mixture of the two. Obsessive-compulsive disorder should be distinguished from obsessivecompulsive personality disorder, which refers, in general, to being preoccupied with rules, details, and schedules. Such individuals often are inflexible about moral issues and the behavior of others. Because they insist that others do things their way, their interpersonal relationships tend to be poor. Normally, they do not experience obsessions and compulsions. Although an important disorder, obsessivecompulsive personality disorder is not used as an example in this book.