5 Types of Mental Illness was last updated May 4, 2016

Mental illness is a condition that affects a person’s thinking, feeling, and behavior. The mainstream medical community recognizes more than 200 classified types of mental illness.

These conditions can alter your ability to relate to other people, work, and attend school, and can prevent you from living a normal life. Different types of mental illness offer different experiences, and symptoms may vary from person-to-person, even when they share the same diagnosis.

There are five major categories of mental illnesses:

It’s important to remember that each condition can vary greatly from person to person.

Stigma and mental illness

When you’re concerned about your mental health or that or that of a loved on, you should talk to a qualified health care provider. Many people with mental illness may feel stigmatized for their condition, but treatment for these disorders has come a long way. Mental illness requires the same need for treatment as many physical ailments.

RELATED: Infographic: 5 Types of Mental Illness

Never Miss a Beat!

Get Mental Health Tips Sent to Your Phone!

Message and data rates may apply. Text STOP5 to opt out and HELP5 for help. Go to UPMC.com/SMS-terms for privacy and terms.

array(11) { ["id"]=> string(7) "sms-cta" ["type"]=> string(4) "form" ["title"]=> string(42) "Get Mental Health Tips Sent to Your Phone!" ["category"]=> string(0) "" ["subcategory"]=> string(0) "" ["keyword"]=> string(7) "MHTOOLS" ["utm_source"]=> string(0) "" ["utm_medium"]=> string(0) "" ["utm_campaign"]=> string(0) "" ["utm_content"]=> string(0) "" ["utm_term"]=> string(0) "" }

Types of Mental Illness

Anxiety Disorders

Anxiety disorders affect approximately 40 million American adults age 18 years and older each year.

Anxiety disorders are a form of mental illness that causes people to experience distressing and frequent bouts of fear and apprehension. Many will experience these feelings when periodically doing things like public speaking or a job interview. Those with anxiety disorders experience these feelings frequently, and for an extended period — six months or more.

If not treated, these symptoms can worsen and increase, including:

  • Panic attacks
  • Physical symptoms such as pain, nausea and headaches
  • Nightmares
  • Obsessive thoughts
  • Fear of leaving the house

Common diagnosis of mental illness, under the category of anxiety disorders, includes:

  • Panic disorder
  • Obsessive-compulsive disorder (OCD)
  • Post-traumatic stress disorder (PTSD)
  • Social phobia (social anxiety disorder)
  • Generalized anxiety disorder (GAD)

Mood Disorders

Every one of us has experienced feelings of sadness, irritability, or a general case of the “blahs” at one time or another.

While bad moods are common, and usually pass in a short period, people suffering with mood disorders live with more sustained and severe symptoms and disruption. People living with this mental illness find that their mood impacts both mental and psychological well-being, nearly every day, and often for much of the day.

It is estimated that one in 10 adults suffer from some type of mood disorder, with the most common conditions being depression and bipolar disorder. With proper diagnosis and treatment, most of those living with mood disorders lead healthy, normal and productive lives. If left untreated, this illness can affect role functioning, quality of life and many chronic physical health disorders such as diabetes and heart disease.

Schizophrenia and Psychotic Disorders

Schizophrenia is a serious brain disorder that is marked by significant changes and disruption in both cognitive and emotional function. Schizophrenia has an effect on the most basic human aspects of life (e.g. language/communication, train of thought, perception of objects, self and others).

The most common symptoms of schizophrenia include:

  • Hearing voices
  • Hallucinations
  • Delusions
  • Social withdrawal
  • Incoherent speech
  • Abnormal reasoning


Dementia is distinguished by a disruption of consciousness, as well as changes in cognitive health, such as memory loss and motor skills.

The most common forms of dementia include:

  • Alzheimer’s disease
  • Health conditions (e.g., head trauma, HIV, Parkinson’s); and
  • Substance-induced dementia (e.g. drugs/alcohol abuse, inhalants, or exposure to toxins).

Eating Disorders

Eating disorders are serious, chronic conditions that can be life-threatening, if left untreated. These conditions typically take root during the adolescent years and primarily affect females.

While there are variations in the expression, symptoms, and course of eating disorders, the common thread is that they all involve obsessive and sometimes distressing thoughts and behaviors, including:

  • Reduction of food intake
  • Overeating
  • Feelings of depression or distress
  • Concern of weight, body shape, poor self-image

At the onset, these disorders begin with the person eating smaller or larger portions than usual. However, over time, urges to decrease or increase the amount of food eaten take hold, and the illness escalates. The three most common types of eating disorders are:

RELATED: Identifying and Treating Eating Disorders

The National Institute of Mental Health estimates that more than 45 million Americans have a mental illness in any given year, with only about half seeking treatment. While the majority of us will have concerns about our mental well-being from time to time, mental illness is diagnosed when there are ongoing and increasing signs and symptoms begin to cause continual stress and impact our quality of life and our ability to function.

For more information on mental and behavioral health, please visit our behavioral health website.


Mental Health SMS Banner

About UPMC Western Behavioral Health

UPMC Western Psychiatric Hospital is a nationally recognized leader in mental health clinical care, research, and education. It is one of the nation’s foremost university-based psychiatric care facilities through its integration with the Department of Psychiatry of the University of Pittsburgh School of Medicine. UPMC Western Psychiatric is the hub of UPMC Western Behavioral Health, a network of nearly 60 community-based programs providing specialized mental health and addiction care for children, adolescents, adults, and seniors throughout western Pennsylvania.