Mental Health

What is the most common mental illness?

Mental illnesses are common throughout the world and affect millions of people. The key difference between these illnesses is their symptoms–some are easy to spot, while others come in a variety of forms. If you’ve ever questioned what mental illness is the most common, read on to learn the answer.

Mental disorders are common in society

Mental disorders are very common in society. In the United States, one in four adults will suffer from a mental disorder at some point during their life. These disorders can affect how you think, feel, and behave. They can happen to anyone, regardless of your age or financial state.

Symptoms of mental disorders

Mental disorders are the most common health problems in the United States. Disorders such as depression, anxiety, addiction, and schizophrenia can have a large impact on people’s quality of life and ability to function normally. The symptoms of these disorders can vary depending on the person. Some signs of a mental disorder include having difficulty concentrating, not feeling like you’re doing well at work or school, or feeling hopeless about the future.

Mental disorders vary by age

Mental disorders are chronic underlying conditions that affect a person’s thoughts, moods, or behaviors.

Mental illness is the leading cause of disability worldwide. The most common mental illnesses are anxiety disorders and depression.


The most common mental illness is stress. This can come in the form of anxiety, fear, or depression. Stress might not manifest itself through symptoms but in the form of emotions that people experience. According to the American Psychological Association, one in five Americans suffer from stress-related disorders, many of which stem because they have no feasible way to alleviate their stress.


Anxiety is a mental or emotional state characterized by feelings of tension, worry, and fear. It is characterized by the person’s tendency to be easily startled and their tendency to anticipate the worst.


Depression is a mood disorder and the most common mental illness according to the National Institute of Mental Health. The condition can lead to feelings of sadness and hopelessness, as well as physical symptoms such as chronic fatigue, sleep problems, social withdrawal, weight gain, headaches and stomach problems.


Schizophrenia is a mental illness that affects the way someone thinks and feels. People with schizophrenia may hear voices, they may not be able to tell what’s real and what’s not, or they might have trouble speaking clearly. Symptoms of this disorder can include delusions, hallucinations, and disordered thinking.

Bipolar disorder

Bipolar disorder is one of the most common mental illnesses. It primarily affects people in their teens and twenties, but it is relatively rare in children. There are no specific causes for bipolar disorder. Certain factors such as genetics, environment, and psychological trauma can all increase a person’s risk of having this condition.


Some experts believe that psychosis affects as many as 2.1% of the world’s population, making it the most common mental illness around the world. Psychosis is a symptom of a larger mental health condition and can range from mild to severe forms. Many people with psychosis experience problems in their relationships and at work because they can’t stick to schedules or remember things.

Personality Disorders

Personality disorders are the most common mental illness in the United States. They affect about 10% of Americans, which is about 25 million people. Personality disorder symptoms vary and each individual will have a different set of personality disorders.


The most common mental illness is depression. It affects nearly 10 percent of Americans at some point in their lives. It can be treated with medication, therapy, or a combination of both. For more information on treatments and the prevalence of mental illness, please read the article “What are other types of mental illnesses?”