Medically reviewed by Katelyn Hagerty, FNP
Written by Our Editorial Team
Last updated 1/11/2023
Mental illness affects a staggering portion of the world’s population — as many as one in five people experience a form of it each year. Unsure whether your condition qualifies as a mental illness? It might help to understand the difference between mental illness versus personality disorder.
Terminology in the mental health community is rarely (if ever) simple because things often change. Manic depression, for instance, is now called bipolar disorder, and bipolar disorder actually has two subcategories.
These are among just the latest modifications to an ever-evolving field of medicine that used to consider bloodletting an appropriate treatment for releasing evil spirits possessing the body.
We digress. Whether you have a personality disorder or are wondering if your diagnosed mental illness is actually a personality disorder, what you’re ultimately trying to do is learn more about your condition (or someone else’s) based on how each is classified.
We’ll walk you through this oft-confusing subject of mental illness versus personality disorder. Let’s start with the basics.
According to the National Library of Medicine, a personality disorder is characterized by a long and often grueling experience of thought patterns and behaviors that are both unhealthy and inflexible.
Many might say being a Nickelback fan fits this definition, so it’s important to go a little deeper and look at the symptoms.
A person with a personality disorder may experience the following as part of their condition:
Poor social function
Distorted views of reality
People with personality disorders tend to struggle to connect with others and function in normal social relationships, social situations or professional roles. Though the symptoms may ebb and flow over time, they often make it difficult for a person to properly integrate or function normally — or to maintain stable relationships, in general.
There are several common types of personality disorders:
Borderline personality disorder
Narcissistic personality disorder
Schizoid personality disorder
Schizotypal personality disorder
Histrionic personality disorder
Paranoid personality disorder
Antisocial personality disorder
Dependent personality disorder
Avoidant personality disorders
Learn more about mental illness versus personality disorder below.
According to the National Institute of Mental Health (NIMH), a mental illness is any disorder that affects cognitive, behavioral or emotional function in a way that causes impairment, dysfunction or distress.
In the clearest terms, any type of personality disorder meets the textbook criteria for mental illnesses. Many things fit this definition, including depressive disorders, anxiety disorders and post-traumatic stress disorder (PTSD).
If you remember back to your high school geometry classes, all squares are rectangles, but not all rectangles are squares. That means a square is always a rectangle, but a rectangle isn’t always a square.
In this case, we can essentially replace “square” with “personality disorder” and “rectangle” with “mental illness.” Any time someone is diagnosed with a personality disorder, they’ve already met the qualifications to have a mental illness.
But here’s where things can get tricky. The NIMH categorizes mental illnesses into two categories: any mental illness and serious mental illness. Any mental illness is typically a milder condition. Low-to-moderate levels of depression or anxiety meet these qualifications.
Serious mental illness, meanwhile, causes such a burden that it limits major life activities. You may not be able to work, maintain personal relationships or take care of yourself.
While depression and anxiety can meet these requirements if they’re severe enough, personality disorders tend to be more difficult to pin down — especially since the people who have them are often reluctant and avoidant of help.
In other words, it can sometimes be hard to determine the seriousness of someone’s personality disorder because they may not seek effective treatment.
Of course, if a personality disorder becomes severe enough to warrant intervention, you can assume it’s serious. After all, this would indicate it’s harming normal day-to-day functions.
But it’s possible for a person with severe personality disorder to function or cope enough to function at the bare minimum while disguising their illness.
There are two ways to look at the question of whether you can have both a personality disorder and a mental illness. Let’s look at the simplest one first.
Since a personality disorder is already a mental disorder, you technically always have a mental illness when you have a personality disorder. So if you have OCD or schizophrenia, you have a mental illness.
But the more complicated (and potentially more important) way of looking at it is to ask whether you can have a personality disorder and another mental illness, like anxiety or depression. And the answer is an emphatic yes.
Research shows a high comorbidity between conditions like borderline personality disorder and mood disorders like depression.
Personality disorders can be extremely difficult to treat. It depends on the “cluster” of personality disorders a person belongs to: A, B or C.
Cluster A disorders include paranoia, schizoid, and schizotypal schizophrenia. Patients in this category who are suspicious or paranoid will often avoid things like group therapy — or therapy in general — out of a lack of trust in the practice and the people involved. If unwilling, they may simply be impossible to treat.
Cluster B patients, on the other hand, can benefit from both group therapy and individual therapy. Antisocial, histrionic, borderline and narcissistic personality disorders can benefit greatly from this introspection.
Lastly, the avoidant, dependent, and obsessive-compulsive personality types in Cluster C can benefit from treatment options like selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT).
Any treatment plan, however, should be carried out with the oversight of a mental health professional, regardless of what the personality disorder sufferer is diagnosed with. And that leads us to our final point.
We’re assuming you made your way to this article to clear up some lingering questions after speaking with a healthcare professional — but that’s not always the case. You may be struggling right now while seeking answers from home concerning signs you’ve seen in your behavior or that of someone you love.
If you’re currently exploring this solo, it’s time to get help.
There are many ways to seek help and support. Existing primary care doctors and counselors, religious and community organizations and even educational resources through a school or university can help support you or someone else.
But it all starts with reaching out for help — nobody’s going to drop solutions in your lap.
If you’re not sure where to begin, let us help you figure things out. Our mental health resources can answer more questions if you have them. And our online therapy platform can connect you with mental health providers 24/7, from the convenience and safety of wherever you are (as long as you have WiFi).
Personality disorders don’t have to define you, and neither do mental illnesses. But until you seek help, they’re going to have more control over your life than you’d ever give them willingly.
Take back that control today.