Guest Post by E. J., INTJ

Identifying the MBTI type of someone with a mental illness, regardless of the kind, can be difficult. It is doubly so when the individual in question has a personality disorder.

A Basic Overview

Note: The personality disorder labels I will be using come from the DSM-5, the diagnostic manual currently used by American psychologists. I realize that other countries tend to use versions of the ICD-10, the World Health Organization’s diagnostic manual, more heavily than the United States does at present. I have tried to include alternate names where I think it is needed for clarity.

For those who are not familiar with personality disorders, there are 10 specific disorders (although the number has varied over time and will probably continue to be revised). They can be organized into three groups—personality disorders that result in odd behaviour, those that result in dramatic or erratic behaviour, and those that result in anxious behaviour. Occasionally someone may be diagnosed with an unclassified personality disorder or a mixture of personality disorders. Unlike most mental illnesses, personality disorders are consistent over time and in a variety of settings. People with the disorders do not experience them as illnesses—the disorders are simply part of the way they function. A person with this category of mental illness generally sees their behaviour as normal and does not want therapy unless they end up with a comorbid illness like depression (in some cases, brought on by others’ negative reactions to their behaviour).

As a result, most people with personality disorders do not usually get diagnosed, much less treated. Learning about the disorders can be a good idea—particularly if you know a “difficult” person and want to respond more effectively to their behaviour. You can’t diagnose them officially, but you can certainly use your research to decide what your strategy should be when you interact with them.