Flat Affect

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Flat affect is a severely restricted or nonexistent expression of emotion. A person with flat affect does not express emotion the way other people do. It is not a condition by itself; it’s a symptom of various other conditions, including schizophrenia, autism, or post-traumatic stress disorder.

Because it’s a symptom of something else going on, people will rarely seek help for just this single symptom. When they are seen for a condition, the healthcare provider can observe that the person has a flat affect.

This article will review the characteristics of flat affect, its various causes, how it's diagnosed, and treatment.

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Symptoms of Flat Affect

Flat affect is, in essence, a “flattening” or dampening of emotions and expression of emotions. This can impact daily interactions, social functioning, and interpersonal relationships.

Symptoms of flat affect can include:

  • Minimal verbal responses
  • Reduced or “flattened” emotional response, such as no recognizable facial emotional changes or expressions
  • No changes in speech intensity, modulation, or tone
  • Detached connection with others
  • Seeming lack of interest in relationships or discussion

Causes of Flat Affect

Flat affect in and of itself is not a disorder; it is a symptom of a larger diagnosis. In order to resolve the flat affect, it’s important to know the underlying cause.

You may display a flat affect with the following conditions:

  • Schizophrenia: A mental health condition involving dysfunction in thinking processes, behavior, and emotion
  • Autism: A lifelong developmental condition that can involve differences in social communication skills, motor skills, speech, and intellectual ability
  • Depression: A mental health condition of low mood
  • Brain damage, like traumatic brain injury (TBI)
  • Parkinson’s disease: A progressive neurological disorder in which brain cells that produce the neurotransmitter dopamine die, which can result in impairments in movement, facial expression, and speech
  • Post-traumatic stress disorder (PTSD): A mental health condition that can develop after exposure to traumatic events
  • Facial paralysis

Sometimes certain medications can cause a flat affect or a significantly blunted affect.

What Medications Can Cause Flat Affect?

Antidepressants can cause flat affect or emotional blunting in some people. One study found that the risk of this effect is increased in people who are prescribed multiple antidepressants, as well as those who take both antidepressants and antipsychotics.

Another study found an association between antidepressants known as selective serotonin reuptake inhibitors (SSRIs) and feelings of apathy and emotional blunting. Medications in this study included:

  • Lexapro (escitalopram)
  • Paxil (paroxetine)
  • Prozac (fluoxetine)
  • Zoloft (sertraline)

Effexor (venlafaxine) was also studied. This, however, is a serotonin-norepinephrine reuptake inhibitor (SNRI), and participants in the study taking SNRIs did not report apathy or emotional blunting.

It’s important to remember that not everyone on antidepressants will experience emotional blunting or flat affect; there may be other underlying neurological or hormonal issues at play in those who experience it.

Antipsychotic medications can also cause flat affect, although studies have been mixed.

How to Treat Flat Affect

Treatment for flat affect will typically depend on the underlying cause. Therapy, medication, or changing medications can be part of that treatment.

Part of the therapy may be to help someone recognize what they are feeling, teaching them about appropriate emotional reactions, and looking at others for emotional and behavioral cues.

Complications and Risk Factors Associated With Flat Affect

Flat affect can impact interpersonal relationships, social situations, work situations, and even everyday functioning.

If you are unable to display emotions or emotional responses, other people may make assumptions that you aren’t interested in them, aren’t invested in the work or the relationship, or don’t like them. Though none of that may be true, people may misinterpret flat affect and react in a negative way.

Depending on the job, flat affect can impact relationships with bosses, clients, or the public, and can limit the types of jobs a person can have. If this happens, the emotional impact of social isolation, job loss, or loneliness can cause significant emotional distress.

Are There Tests to Diagnose Flat Affect?

Flat affect is observable when interacting with a person with this symptom. For example, a healthcare provider will be able to notice it during an appointment.

There is no specific test to evaluate flat affect. A psychologist or psychiatrist will note a person’s affect as part of a clinical encounter or interview. A healthcare provider like a neurologist or physician will note a person’s affect as part of a general overview or evaluation during an encounter.

A person’s affect can give a healthcare provider clues or insight into possible diagnoses to explore.

If someone has been diagnosed with schizophrenia, various tests can measure blunted affect, including:

  • Brief Negative Symptom Scale (BNSS)
  • Brief Psychiatric Rating Scale (BPRS)
  • Clinical Assessment Interview for Negative Symptoms (CAINS)
  • Negative Symptom Assessment (NSA-16)
  • Negative Symptom Subscale of the Positive and Negative Syndrome Questionnaire (PNS-Q)
  • Scale for the Assessment of Emotional Blunting (SEB)
  • Scale for the Assessment of Negative Symptoms (SANS)

When to See a Healthcare Provider

Flat affect is generally a symptom of a larger condition. If you find yourself not being able to recognize emotions, or if others are letting you know that something’s not quite right with how you appear, see a healthcare provider.


Flat affect is a symptom in which a person experiences emotional flattening or blunting. The person does not express emotion as other people do. It is not a condition but a symptom of another condition, such as schizophrenia, Parkinson’s disease, or depression.

A mental health provider or other healthcare provider can often discern flat affect during a clinical encounter. Various tests will be done depending on what they suspect as the underlying cause. Treating the underlying cause can help. Therapy may help the person recognize emotions and develop emotional responses.

A Word From Verywell

Flat affect is a symptom of an underlying cause, such as a severe mental health condition. Fortunately, it can be resolved when the underlying condition is successfully treated. Therapy, medication, or changing medication under the supervision of your healthcare provider should get you the relief you need.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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