Yes, but don’t worry, chances are if you’re taking an antidepressant your personality probably wasn’t too sweet to begin with.

A personality consists of one or more made-up labels that supposedly describes your typical pattern of emotion, cognition, and behavior.

Contrast this to the DSM definition of a mental disorder as a “significant disturbance
in an individual’s cognition, emotion regulation, or behavior” and you will notice they sound more or less the same. But are they?

To examine this point, let’s look at generalized anxiety disorder.

These are the DSM criteria:

• Excessive anxiety and worry (apprehensive expectation), most of the time, for at least six months, about a number of events or activities.
• Worry is hard to control, and is associated with at least 3 of:
  • Restlessness or feeling keyed up or on edge
  • Being easily fatigued
  • Difficulty concentrating or mind going blank
  • Irritability
  • Tension
  • Sleep disturbance

And these are some questions from a scale designed to screen for GAD:

• Are you a worrier?
• Do you worry about your health?
• Do you worry about awful things that might happen?
• Do you often worry about things you should not have done or said?
• Do you suffer from “nerves”?
• Have you often felt listless and tired for no reason?
• Would you call yourself tense or “highly-strung”?
• Do you suffer from sleeplessness?

Those would seem to map on fairly well to the DSM criteria. The only problem is that they aren’t questions from a GAD scale, they’re questions from a personality questionnaire.

Almost every single personality classification system, and certainly every popular/well-researched one, has the trait/domain neuroticism. Some systems don’t call it neuroticism, but don’t let the names fool you, it’s in there. The other popular name for neuroticism is negative affectivity, which is appropriate considering it’s usually defined as the tendency to experience negative emotions.

Here are some other questions from neuroticism scales, you can tell me if they sound like something a psychiatrist might ask a patient:

• Have you ever wished that you were dead?
• Do you often feel life is very dull?
• Are you often troubled by feelings of guilt?
• Does your mood often go up and down?
• Do you ever feel “just miserable” for no reason?
• Do you get palpitations or thumping in your heart?
• Do you get attacks of trembling and shaking?

I took these from the Eysenck personalty scales, arguably the second most common scale/system for classifying personality.

The most popular personality instrument would be the NEO-PI-R, which rates people on the “Big Five” personality traits: neuroticism, extraversion, conscientiousness, agreeableness, and openness.

The neuroticism scale from the NEO-PI-R has six sub-scales or facets, so again, you can tell me if any of them sound like something that we might find in the DSM:

• Anxiety
• Depression
• Hostility
• Self-consciousness
• Vulnerability to stress
• Impulsiveness

Unfortunately, the NEO-PI-R isn’t in the public domain, but the Big Five Inventory is, and its items ask if you are someone who:

• “Tends to feel depressed, blue.”
• “Worries a lot”
• “Often feels sad”
• “Is shy, inhibited”
• “Relaxed, handles stress well” (reversed)
• “Keeps their emotions under control” (reversed)
• “Remains calm in tense situations” (reversed)
• “Feels secure, comfortable with self” (reversed)
• “Rarely feels anxious or afraid” (reversed)

So what is the difference between neuroticism and depression, GAD, social anxiety, panic disorder, etc.?

In theory it’s the time frame.

Depression, as in a major depressive episode, involves a change from your baseline in mood over a discrete period of time lasting two weeks or longer. It is, by definition, a change from your normal self, and is supposed to be severe enough that it causes “clinically significant distress or impairment in social, occupational, or other important areas of functioning.”

But there is another “mood disorder” called “persistent depressive disorder” which used to be called “dysthmic disorder” (DD) that is defined as mild low-grade “depression” (e.g., HAMD score 11-19) for two or more years.

“Two years isn’t a lifetime, that’s not personality.”

That would be a useful point if DD only lasted two years, but I’m afraid most won’t be that lucky. (1, 2). DSM: “Persistent depressive disorder often has an early and insidious onset (i.e., in childhood, adolescence, or early adult life) and, by definition, a chronic course.”

Childhood/early adult onset, present most of the time in most circumstances, stable course? Sounds kind of like the DSM description of the course of a personality disorder: “an onset in adolescence or early adulthood, is stable over time”.

Funny enough, DD replaced what was previously called “depressive personality disorder” (DPD) because Robert Spitzer, the guy who thought DSM-II didn’t have enough diagnostic categories, decided it sounded better. Everyone with DPD had their diagnosis change to “dysthymic disorder – early onset” (and eventually, “mixed personality disorder”).

So it would be unfair to say that neuroticism is the same thing as a major depressive episode, at least conceptually, but it sure as shit sounds a lot like DD and DPD, and GAD.

Similarly, anxiety disorders like GAD and social anxiety disorder could, in theory, only be present for a few months and not represent long-standing patterns of emotions and behavior. Does GAD last for only a few months?

DSM: “Many individuals with generalized anxiety disorder report that they have felt anxious and nervous all of their lives.” Right…

The “symptoms” of anxiety and depression no doubt fluctuate in response to life, but many people experience a low-grade version of these “symptoms” throughout their life, in which case personality psychologists and other psychiatrists (with a different theoretical tilt) have decided they should be called “traits” instead of symptoms, and usually under the broader label neuroticism or one of the DSM personality disorders.

The question is, do neuroticism scores decrease when you take antidepressants?

Yup (1, 2, 3), and they beat placebo (4), and you don’t need a DSM diagnosis (5, 6).

“But that’s only a couple studies!”

“There isn’t a good level of evidence!”

“You need more research before you can say that!”

I actually don’t need any more research. I didn’t need any research.

Neuroticism questionnaires and depression/anxiety rating scales measure the same fucking things. Not theoretically, but empirically. Pretend conceptual distinctions don’t mean shit if the scale content overlaps. You could literally re-create the GAD-7 and PHQ-9, and the respective DSM criteria, almost word for word, with items from the EPQ and other neuroticism questionnaires.

There might be some sort of a MDD-type illness that is biologically separable from trait neuroticism, I’m not convinced that isn’t possible. I’m just not convinced it’s being measured exclusively by depression rating scales, or that depression/anxiety scales measure something that neuroticism questionnaires don’t.

The correlations between “neuroticism” questionnaires and the “symptoms” of depression and anxiety can be as high as .70-.90 (e.g., 1 2 3 4). That’s as, if not more, correlated than the various anxiety/depression scales are correlated with each other! Different versions of the same scale sometimes don’t even correlate that strongly.

This meta-analysis found a difference between DD/GAD/Panic/SAD/MDD patients and controls on neuroticism scores with a massive effect size, in the range of d=1.50-2.00, and that is for total neuroticism scores. Had they matched each “facet” with the respective diagnosis (e.g., “depression” with DD/PDD, “anxiety” with GAD/Panic, etc) I can only imagine.

And this is why decades of research on the “link” between neuroticism and depressive/anxiety disorders, funded by millions of dollars, has been a waste of time. The one “link” you people needed to worry about is that when two scales have almost identical items and are highly correlated it means they are probably measuring the same fucking thing.

You wanted to know why some people have depressive/anxiety disorders and other people don’t. You thought maybe “personality” is a “risk factor.” A correlation with neuroticism offers the pretense of an explanation, because one construct is called a “mental illness” and the other is called a “personality trait.” But a correlation here doesn’t really explain anything.

All a cross-sectional relationship tells you is that many people who have been depressed/anxious over the last 1-2 weeks have been kinda depressed and anxious on and off throughout most of their lives. And the only thing a prospective relationship tells you is that people who are often mildly depressed and anxious are more likely to be more depressed and anxious at some point in the future. Strong work. Could we not have put that grant money towards something more interesting, like Westworld?

So if you accept that antidepressants can decrease HAMA/HAMD/BDI/GAD-7/PHQ/whatever scores then why the hell wouldn’t they decreased neuroticism questionnaire scores that measure a mild/chronic version of the same thing?

The irony of that question is, in addition to wasting a whole bunch of time and money, we’ve spent quite a bit of time telling patients with “personality disorders” that they don’t have a “mental illness” so they need “psychotherapy” instead of “medicine” (in other words, “you’re a pain in the ass, get out of my office”).

But the effect sizes for antidepressants (vs. placebo) are higher for chronic mild depression/anxiety – which could be measured with the NEO-PI-R or EPQ just as easily as the HAM-D/HAM-A – than they are for the “major” depressive episodes.

• Major depressive episode: d = 0.3 (1)
• GAD/SAD/Panic: d = 0.5-0.9 (2)
• Dysthymic disorder: d = 0.5 (3)

This probably happens for no other reason than “chronic” things are unlikely to get better on their own after 6 weeks of taking a placebo, whereas severe, short-lived, episodic things are… episodic, and often fizzle out on their own over time.

This could be one argument against arbitrarily proclaiming every effect size higher than 0.5 to be clinically significant. But “this means depression and anxiety disorders are just normal personality variants, not mental illnesses” is not the point of this post. That would be equally as stupid as concluding “this means neuroticism isn’t a normal personality trait, it’s a real mental illness that needs real medicines.”

The point of this post is that giving something a different name doesn’t make it a different thing. Neither your monoamine receptors/transporters, nor the medications that bind to them, read the DSM. They don’t care if you call something a “personality trait” or a “symptom” of a chronic “mental disorder.”

Your personality is nothing other than your typical pattern of thinking, feeling, and acting, and psychoactive substances can change the way you tend to think, feel, and act. You have no special “essence” or “being” or “soul” inside of you. There’s nothing hidden away in your pineal gland, protected from your neurotransmitters by a mind-brain barrier.

Will you become an entirely different person by taking Zoloft? Probably not, but there’s no reason why altering your brain chemistry doesn’t have the capacity to change your “personality” to some degree. If anybody tells you otherwise they probably think far too highly of themselves.