What is a flat affect? Is it a negative mental health symptom?

What Is a “Flat Affect” Mood?

It’s important to understand that one’s affect is different from their mood. 

A flat affect happens when an individual’s face or affect is not expressive, showing no emotion even while feeling distinct emotions like joy, sadness, or frustration. Someone is only showing a flat affect when there is absolutely no emotion shown on their face and that expression is incongruent with what they are feeling.

This is also referred to as a constricted affect. Multiple conditions can cause a flat affect, but the reason it occurs can be different for each condition.

What Is an Example of a Flat Affect?

An example of having a flat affect would be when you are feeling happy and want to express it,  but your face isn’t showing a smile. 

It’s different from being bored or simply expressionless. Again, not only does your face not show any emotion, but you are feeling emotion on the inside.

What Mental Illness Causes a Flat Affect? What Causes Someone to Have a Flat Affect?

A flat affect can occur for a variety of reasons. Examples include:

• Schizophrenia 
• Autism
• Depression
• Parkinson’s (due to motor neurons)
• Medications (first-gen antipsychotics)
• Freeze response

Though this symptom is often associated with mental health conditions, physical conditions or other specific scenarios may also be responsible. Because flat affect has so many causes and is not a symptom consistently present in associated mental health conditions, it is not included in diagnostic criteria for conditions like schizophrenia or depression.

What Is a Blunted vs. Flat Affect?

The main difference between having a flat affect versus a blunted affect is that flat means that no emotions are showing — it reflects 0% of one’s internal experience. A blunted affect, on the other hand, means that only most of one’s emotions are not expressed on one’s face, with around 25-30% of the internal emotional experience being reflected. A blunted affect means that there is a noticeable lack of emotion, but some is still expressed.

As with a flat affect, a blunted affect can be a side effect of medication. When caused by either medication or Parkinson’s, it is due to a limited ability to move one’s facial muscles.

However, when either a blunted or flat affect occurs due to a mental health disorder like autism, it is possible to learn to express emotions on one’s face, but often, the individual does not understand the connection between facial expressions and emotions.

What Is an Example of a Blunted Affect?

A common situation where someone could exhibit a blunted affect is during a period of intense depression. With depression, it’s common to see people showing low or limited expressions, even when seeing something joyful and feeling momentarily happy. 

However, this would not be an example of having a flat affect, since there would still be some expression of emotion. “Blunted” means having a limited range of expression.

What Is a Flat vs. Blunted vs. Constricted Affect?

“Constricted affect” is an encompassing term that can refer to both a flat and/or blunted affect. A person with a constricted affect may also have body language that doesn’t match their internal emotions — for example, someone could be anxious, but they aren’t wringing their hands or shifting around.

Though a constricted affect can be a symptom of multiple mental health disorders, it is not a true sign of any specific condition without other symptoms to confirm the diagnosis.

What Is a Labile Affect?

A labile affect is the opposite of a constricted affect. If someone has a labile affect, their expressions are erratic, swinging up and down in (expressed) mood frequently. For example, someone’s expression could move quickly from laughing to crying. These expressions can still match someone’s internal experience and are not necessarily incongruent.

Is a Flat Affect a Negative Symptom of Schizophrenia?

Technically, a flat affect would be classified as a negative symptom, but it may not mean what you think. There are three types of symptoms in schizophrenia: negative, positive, and cognitive. These are not related to whether the symptom is a good or bad sign for the disorder. They are actually related to what the patient is seeing or experiencing that is incongruent with the world within and around them. 

A “negative” symptom classifies symptoms that indicate an absence or lack of standard mental functioning. Examples of this would be not seeing something that should be there, moving slowly, or exhibiting a flat affect. In turn, “positive” symptoms of schizophrenia are associated with the ability to tell what’s real from what isn’t, such as seeing something that isn’t there or having hallucinations.

Is a Flat Affect a Positive or Negative Symptom?

In terms of whether a flat affect is a sign of a positive or negative symptomatic progression, it can be indicative of either, but it’s not usually a clear sign of one or the other. 

With autism, flat affect is a standard symptom and may indicate an individual is either not masking or has not learned to express the emotions that they feel (or both). With schizophrenia, it can often be a standard symptom or, if someone had been making specific progress, it could be identified as a negative step back. 

Again, though, a flat affect is not a sure sign of a mental health disorder, so it is important to speak with a primary care doctor or a mental health professional about your experience.

Treatment Options for a Flat Affect

Treatment for a flat affect will vary depending on the cause. It is most important to address the underlying issue, rather than the one specific symptom. 

Those with autism and schizophrenia can be taught and trained to increase their emotional expression. Individuals will work with a mental health professional and talk through why their expressions may not be showing up.

In the end, having a flat affect is also unlikely to have a serious negative impact on its own. If you are worried about what might be causing it, speak with a mental health professional or a primary care provider to assess what the source might be.