There are a number of systems for classifying and diagnosing mental health problems. We are going to look at a frequently used one called DSM.
DSM stands for Diagnostic and Statistical Manual of Mental Disorders and is published by the American Psychiatric Association.
"Abnormality" is a difficult term to define: each culture, time period and society has a unique set of standard norms: any departure from these could be seen as abnormal.
Deviation from these norms can easily be used to justify hatred, prejudice and cruelty.
Social norms and rules also change over time: the accepted role of women in society has changed and evolved over time periods, and many "abnormal" behaviours, such as women having a career, are seen as normal today.
Abnormality can be defined as a "deviation from statistical norms", such as having a low IQ or showing statistically infrequent behaviours. However, this does not take into account the desirability of behaviour: having a very high IQ is abnormal but not a negative quality.
It also makes no distinction between rare but harmless behaviour and rare but dangerous behaviour: having an IQ twenty points above average is rare but harmless, but showing aggressive behaviour outside the norm is rare but dangerous.
Failure to function adequately
this gives various criteria for diagnosing
abnormal behaviour, such as
•Dysfunctional Behaviour: Behaviour that goes against prevailing social norms
•Observer Discomfort: Behaviour which causes others to be uncomfortable or embarrassed
•Unpredictable Behaviour: Behaviour which seems to not be under control and cannot be predicted
•Irrational Behaviour: Behaviour which has no logical basis or explanation
•Personal Distress: Behaviour which is excessively informed by emotional state
Failure to function adequately
In reality, it is hard for any single individual to meet all six of these: they are also a subjective list of what constitutes "ideal" mental health
Antisocial personality disorder. An example of a disorder defined largely by deviation from social norms.