The most common mental health diagnoses among Americans are anxiety disorders , followed closely by depressive disorders. Anxiety conditions like generalized anxiety disorder affect the largest share of people each year, with depression also impacting tens of millions of adults.

Most common diagnoses

  • Anxiety disorders are the single most common group of mental illnesses in the U.S., affecting roughly about 1 in 5 adults in a given year in recent estimates.
  • Within this group, generalized anxiety disorder (GAD) and unspecified anxiety disorder appear at the top of diagnosis lists in large health-claims datasets from 2024.

Other highly common conditions

Beyond anxiety, several other diagnoses show up very frequently in U.S. data:

  • Major depressive disorder and other depressive disorders are among the most frequently diagnosed conditions and affect well over 1 in 10 adults over a year in some recent estimates.
  • ADHD , especially in its combined or inattentive presentations, is one of the top primary mental health diagnoses in claims data.
  • Substance use disorders , particularly opioid dependence , appear in the top tier of diagnoses in recent national datasets.
  • Conditions like PTSD , bipolar disorder , and autism spectrum disorder are less common than anxiety and depression but still affect millions of Americans.

Why “most common” can vary

When people ask “what is the most common mental health diagnosis amongst Americans?”, the answer can differ slightly depending on:

  • What is being counted
    • Any mental health symptoms vs. formally diagnosed disorders.
    • A single “primary” diagnosis vs. all diagnoses a person might have.
  • Which data source and year
    • Insurance claims, national surveys, and clinical samples all capture different slices of the population, so rankings can shift slightly from one dataset or year to another.

Despite these differences, anxiety disorders consistently come out on top as the most common group of mental health diagnoses in the United States, with depression a close second in overall burden.

Information gathered from public forums or data available on the internet and portrayed here.