Just a word of warning before we enter the fascinating world of psychological disorders. It's a standard warning I give before every abnormal psychology class and lecture. Be cautious about applying what you learn here to your family, friends, co-workers and neighbors. Inevitably when we read about one disorder, someone in the class tells us about a sibling, a coworker or someone who has or whom they think has that disorder. Diagnosing psychological disorders is a complex process and we need to respect those around us. So, as much academic fun as it is to play "Dr. Freud", we need to maintain those ethics and not try to play therapist.
Having said all that, how do we know when someone's behavior is "abnormal"? Think about the behavior of those you saw on Halloween, especially that of adults. Was it "abnormal"? It's probably safe to say that many people behaved in ways they would not ordinarily behave. And much of it was probably outside the lines of "normal." Do they have a disorder? You can see that deciding what behavior is abnormal can be difficult.
Psychologists generally use seven criteria for determining behavior that is considered abnormal. (One aside: Even the use of the term abnormal is controversial because of the labeling effect that occurs. Once labeled as abnormal, it can be difficult to escape the connotations of that label.)
The criteria are:
1) behavior is unusual, not just statistically deviant
Think is statistical deviance in this way:
How many students do you know who have a perfect 4.0 GPA?
Not many - probably a small percentage, thus those with a 4.0 are statistically deviant. Would we call them abnormal? Probably not.
2) the person has a faulty perception or interpretation of reality
3) the person is in severe personal distress. In other words, the behavior is bothersome to the person not just to others. For many of the homeless who are mentally ill, their behavior is not personally distressing. It is just bothersome to us.
4) the behavior is self-defeating. Again, this could be open to dispute
5) the behavior is dangerous
6) the behavior is socially unacceptable
This criteria is where the cultural component of mental illness comes in. Different cultures see different behavior as acceptable and there is not 100% concordance among all cultures concerning what is and isn't a psychological disorder.
Diagnosis of a disorder is made by using the Diagnostic and Statistical Manual IV (DSM IV). This lists the symptoms, length and severity that are necessary for diagnosis. It changes with time and there are many disorders taken out while others are added each time it is revised. The DSM allows for standardization of diagnosis but it also presents problems since it labels the individual. This is a bigger problem in today's computerized world.
In this unit we will explore the major categories of psychological disorder as well as specific disorders.