All You Need to Know About Flat Affect

Medically Reviewed By Kendra Kubala, PsyD
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Flat affect is the near or total absence of typical emotional responses. It is associated with several conditions, including autism, schizophrenia, and depression. The exact cause of this symptom is unknown, but treating the underlying condition can help address it.

This article discusses flat affect in more detail, including the symptoms, causes, treatments, and related conditions.

What is flat affect?

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The American Psychological Association defines flat affect as the “total or near absence of appropriate emotional responses to situations and events.” It is not a condition in itself but a symptom of other conditions.

Flat affect is commonly associated with certain mental health and neurological disorders. A person experiencing flat affect may appear detached or cold. They may be unable to express the emotions they are feeling in the same way as a person without flat affect. They may also find it difficult to react verbally in the emotional way that others expect.

If you or someone you know seems to be experiencing flat affect, contact a doctor or mental health professional. They will be able to diagnose any underlying and associated conditions that may be causing the flat affect.

What are the symptoms of flat affect?

Someone who is experiencing flat affect may have difficulty empathizing with those around them. They may also have trouble picking up on emotional cues from other people.

Other signs of flat affect may include:

  • monotone voice
  • difficulty making eye contact
  • lack of facial expressions
  • little to no verbal or nonverbal emotional expression
  • a sense of apathy

A few conditions are associated with flat affect.


Schizophrenia is a serious psychological condition. It affects how you think, behave, and feel. Many people with schizophrenia appear to lose touch with reality.

The symptoms of schizophrenia include:

  • psychotic symptoms, including delusions and hallucinations
  • negative symptoms, such as difficulty showing emotion
  • cognitive symptoms, which include issues with attention, concentration, and memory

Most people who experience schizophrenia receive a diagnosis between the ages of 16 and 30 years. Early diagnosis and treatment can help you participate more effectively in day-to-day life. Treatment for schizophrenia typically includes a combination of medication and therapies.

Learn more about schizophrenia.

Schizoid personality disorder

Schizoid personality disorder is a psychological condition that often causes someone to appear aloof, disengaged, and distant. It affects less than 1% of the population.

The symptoms of schizoid personality disorder include:

  • detachment from social relationships and interactions
  • restricted range of expression of emotions
  • no desire for personal relationships
  • continually choosing solo activities over group ones
  • little to no interest in sexual activity
  • appearing indifferent to praise or criticism
  • lacking close friends or confidants
  • taking pleasure in few activities
  • showing emotional detachment, coldness, or flat affectivity

The treatment for schizoid personality disorder often includes a combination of medication and psychotherapy.

Learn more about schizoid personality disorder.

Autism spectrum disorder

Autism spectrum disorder (ASD) is a developmental and neurological disorder. The symptoms typically begin to show in the first 2 years of life. However, it is possible to diagnose ASD at any time.

Autism is a “spectrum” disorder because of the wide array of symptoms that people may experience. The type and severity of symptoms can vary among individuals.

Some of the symptoms that a person with ASD may experience include:

  • having restricted interests or repetitive behaviors
  • difficulty communicating and interacting with others
  • infrequently sharing interests and emotions with others
  • having difficulty with conversations
  • displaying facial expressions or gestures that do not match the situation
  • difficulty displaying empathy
  • having a tone of voice that is flat, robotic, or singsong

The treatment for ASD typically involves a combination of medication and psychological, behavioral, and educational interventions.

Learn more about autism spectrum disorder.


Depression is a common but potentially serious mood disorder. It affects how you think, feel, and handle daily activities.

Not everyone will experience the same symptoms of depression. Typically, the symptoms must last longer than 2 weeks to warrant a diagnosis of depression.

Some of the symptoms of depression you may experience include:

  • feeling persistently sad or anxious
  • experiencing an “empty” mood or flat affect
  • feeling hopeless or pessimistic
  • losing interest in hobbies or activities
  • decreased energy or fatigue
  • difficulty sleeping
  • changes in appetite
  • aches, pains, or headaches

If you are experiencing symptoms of depression, contact a doctor or mental health professional. The treatment for depression typically involves a combination of medication and psychotherapy.

Learn more about depression.

Other conditions

Flat affect also has an association with other conditions, including traumatic brain injury and post-traumatic stress disorder (PTSD).

Learn more about PTSD.

What causes flat affect?

Flat affect is one symptom of various mental and developmental conditions. The exact cause of many of these conditions is unknown.

However, certain risk factors may play a role in the development of any one of these conditions. These factors include:

  • Genetics: Having a family member with a psychological or developmental condition can mean that you have an increased risk of developing one.
  • Environment: Certain environmental factors may increase your risk of developing one of these conditions. These factors include:
    • stressful or dangerous surroundings
    • exposure to viruses or nutritional issues before birth
    • low birth weight
    • having older parents
  • Brain structure and function: Unusual levels of certain chemicals in your brain may lead to the development of conditions such as depression. It is also possible that certain areas of the brain are a different size in those who develop schizophrenia and related conditions.

How do you treat flat affect?

The treatment of flat affect largely depends on the condition causing it. Each condition that is related to flat affect has its own treatment process. A doctor or mental health professional can work with you to find the most effective treatment for your situation.

Some of the treatment options may include:

  • Medication: Medications to treat the causes of flat affect are:
    • antidepressants
    • antipsychotic medications
    • anti-anxiety medications
  • Therapy: Types of therapy that may help treat the causes of flat effect include:

Learn more about psychotherapy.


Flat affect is a symptom of various psychological and developmental conditions. It is the near or total absence of typical emotional responses.

People who are experiencing flat affect may find it difficult to communicate their emotions through facial expressions or verbally. Flat affect may make them appear detached or cold.

Conditions that are often associated with flat affect include ASD, depression, and schizophrenia.

If you are experiencing flat affect or any of the other symptoms of one of these conditions, contact a doctor or mental health professional.

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Medical Reviewer: Kendra Kubala, PsyD
Last Review Date: 2022 Aug 16
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