This isn’t always the case, though.įlat affect can result from a decreased emotional response to events around you. In some cases, a flat affect may be present along with related symptoms, like anhedonia, or the inability to feel pleasure. DepressionĪs you may know, depression exists on a spectrum. Some forms of dementia can cause changes to the frontal and temporal lobes of the brain, which can sometimes manifest behaviorally as a flat affect.Īlthough not always the rule, symptoms of dementia may include progressive aphasia (the inability to communicate) and a loss of facial expression, according to the National Institute on Aging. Some autistic people may have a hard time expressing emotions or responding to social interactions, which can present as a flat affect.įor example, in a small 2019 study, researchers found that autistic people had more muted muscle movements in their faces when watching films designed to stimulate emotions than a control group. This may sometimes include a flat affect, which has confused experts for decades because the two conditions are very different. Research shows an overlap in symptoms between schizophrenia and autism.

In this case, the reviewers were taking either: In a 2017 study that examined 3,243 user reviews of antidepressants from three health websites, 41% of reviews reported negative emotional and behavioral effects, including a flat affect. Antidepressant medicationsĬertain medications, like antidepressants, can cause a flat affect. While a flat affect is most commonly associated with symptoms of schizophrenia, this isn’t the only explanation for it. More specifically, certain parts of your brain, like the sensorimotor system or the amygdala, may be underactive compared with people who don’t have a flat affect. While researchers don’t know the exact cause of a flat affect, it may be related to brain chemistry.

Flat vs blunted affect