Does my Ex actually have a personality disorder?

Or are they just behaving badly?

Divorce Law has traditionally required a “blame” reason to be cited as the reason for your marriage being “irretrievably broken. This law changed in the UK in April 2022, when the “no fault” divorce was introduced. 

Apportioning blame can help to relieve feelings of guilt and shame, thus enabling an individual to feel better and justify their actions. Blame can also help to relieve hurtful feelings related to being wronged. Blaming another person for a failed relationship can open a Pandora’s box of thoughts, feelings and behaviours. 

Often, a reason for any relationship to falter in the first place, is related to the behaviour of one or both parties. This has quite often been a slow burn in the background, which has finally led to an intolerable situation. 

Fairy tale romance stories tell us that we should be on a quest to find our one true soul mate. You are supposed to meet, fall in love in a whirlwind of feel-good hormones, get married and live happily ever after. Yeah-right! 

Pre marriage, you are both keen to show off and be your best self. After all if you do not both do this, you will break up early on. When you are “in love”, it can be easy to gloss over your partner’s behaviour and think to yourself that “they will change” or even worse “I can change them.” 

It is often, only after the metaphorical confetti has settled and partnered or married life starts that you really get to know someone.  

So where do the undesirable behaviours come from?

An important starting point is to think about personality and why your Ex-partner behaves in the way they do. This is not all one sided however, as your own personality influences how you behave and react to your Ex-partner. 

Here are some definitions: 


We all have different personality traits which influence how we think, feel and behave. These traits develop as we grow up and are usually formed by our early 20s. They also usually stay the same as we get older. An individual’s personality is influenced by experiences, environment and inherited characteristics. 

Personality disorder

Sometimes individuals develop a Personality Disorder as they grow up. But it is important to note that not all bad behaviour can be attributed to a personality disorder. 

The DSM-5 (Diagnostic and statistical Manual of Mental Disorders) defines personality disorder as “an enduring pattern of inner experience and behaviour that deviates markedly from the expectations of the individual’s culture”. You can read more about Personality disorder here 

The DSM classification subdivides the types further and two of the personality disorders, which can cause controlling behaviour are: 

  • Narcissistic personality disorder: characterised by the consistent need for praise and admiration and a belief that they are special and “entitled.” Extreme jealousy, arrogance, and a lack of empathy are also usually present.

  • Obsessive-compulsive personality disorder: this is different from obsessive-compulsive disorder and is characterised by conforming to rules and moral codes on a severe and unyielding basis. Excessive orderliness is also usually present.

I have highlighted and underlined the words extreme, excessive and severe to highlight that these are problem behaviours rather than personality traits. 


How common is Personality Disorder?

The Royal College of Psychiatrists (UK) cites a 2006 study, which gives a figure of 1 in 20 people. You can read their advice leaflet for personality disorder here.  

The difference between Personality and Personality Disorder can be confusing, but a useful rule of thumb is to think of Personality Disorder being a problem behaviour reserved not just for you and your experience of your Ex-partner. The problem behaviours may well have been noticed by other family, friends and work colleagues. Individuals with Personality Disorder have problem behaviours which have been present for many years. 

The next blog post will look at Narcissistic Personality Disorder in more detail.