The 5 Most Common Mental Disorders

Mental health disorders, sometimes referred to as mental illnesses, affect the thoughts, moods and behaviors of those impacted. Although there is no clear link between genetics and the likelihood of having a mental health disorder, lifestyle factors such as diet, substance abuse and an individual’s activity can influence the onset of depression, anxiety and other conditions.

Mental health disorders may be occasional or chronic. And they affect an individual’s ability to relate to others and function day to day. While there are some steps to improve overall mental health, some disorders are more serious and may require professional intervention, temporarily or long term.

Below are the five most common mental health disorders in America and their related symptoms. This list of mental disorders is not all-inclusive; there are many that are not discussed below that may require additional mental disorder test options to find a treatment plan. In general, always consult with a mental health professional if you think you may have a mental disorder.

Anxiety Disorders

The most common category of mental health disorders in America—anxiety disorders—impacts approximately 40 million adults 18 and older. Anxiety disorders cause people to experience distressing and frequent fear and apprehension. While many may experience these feelings during a job interview or public speaking event (as that can be a normal response to stress), those with anxiety disorders feel them commonly and in typically non-stressful events. And bouts of anxiety can last up to six months or more at a time. “Anxiety” is actually a blanket term that includes a host of specific disorders, including the following:

Generalized Anxiety Disorder (GAD): One of the most common mental disorders, GAD is characterized by excessive worry about issues and situations that individuals experience every day. Any worrying that is out of proportion to the reality of the situation may fall under this disorder.

Obsessive-Compulsive Disorder (OCD): A condition featuring recurring, uncontrollable thoughts or behaviors that an individual may feel an urge to repeat over and over.

Panic Disorder: Someone who experiences frequent, sudden panic attacks may be diagnosed with panic disorder. Having a panic attack does not mean an individual has panic disorder; instead, a pattern of panic attacks more often leads to this diagnosis.

Post-Traumatic Stress Disorder (PTSD): A mental health condition that is the result of a triggering, traumatic event. Those who experience violent combat or witness a terrifying event may develop PTSD.

Social Anxiety Disorder: Fear and anxiety over being around others or feeling watched or judged may be diagnosed as social anxiety disorder. This condition makes it difficult for those impacted to build and maintain healthy relationships.

Mood Disorders

An estimated one in 10 adults suffers from some type of mood disorder. While it’s normal to experience mood swings from time to time, people with mood disorders live with more persistent and severe symptoms that can disrupt their daily lives. Depending on the specific disorder, people may experience an ongoing sad, anxious or “empty” mood; feelings of hopelessness; low self-esteem; excessive guilt; decreased energy and more. Therapy, antidepressants and self-care can help treat mood disorders. The most common mood disorders are:

Major Depressive Disorder: This condition, sometimes referred to as clinical depression, is characterized by two or more weeks of consistent low mood and loss of interest in daily life. Some people live with major depressive disorder their entire adult lives.

Bipolar Disorder: This mental illness is characterized by unusual, extreme shifts in an individual’s mood, activity levels, energy and concentration. This condition was formally called manic depression.

Substance-Induced Mood Disorder: Any mood disorder that occurs because of abusing substances of medications is considered a substance-induced mood disorder. This may include depression, anxiety or psychosis.

Psychotic Disorders

Those suffering from psychotic disorders may be unable to understand what’s real and what’s not. This group of mental disorders changes an individual’s sense of reality. Scientists believe that certain viruses, problems with how specific brain circuits work, extreme stress or trauma and some forms of drug abuse may play a role in the development of psychotic disorders. The most common psychotic disorders include the following:

Schizophrenia: This serious mental disorder causes people to experience an abnormal reality. They may have delusions, hallucinations or disordered thinking or behavior.

Schizoaffective Disorder: A sort of combination between a psychotic disorder and a mood disorder, schizoaffective disorder causes people to experience both psychosis symptoms, including hallucinations, and mood symptoms, such as depression or anxiety.

Delusional Disorder: This disorder is characterized by a “fixed false belief based on an inaccurate interpretation of an external reality despite evidence to the contrary,” according to the National Institutes of Health. Those with delusional disorder do not know that they are not experiencing reality.


Although mistakenly thought to be a single disorder, dementia is a term that covers a wide range of specific mental conditions. Those suffering from dementia-related disorders may experience a decline in their cognitive abilities—often severe enough to impair daily life and independent function. While this category includes a host of conditions, Alzheimer’s disease accounts for 60 to 80% of dementia cases. It slowly destroys memory and thinking skills and, eventually, strips the ability to carry out the simplest tasks. Other forms of dementia take the form of Parkinson’s disease, Frontotemporal dementia, Huntington’s disease or Wernicke-Korsakoff syndrome.

Eating Disorders

Eating disorders are about more than an individual’s relationship with food. They’re complex mental disorders that often require intervention from medical and psychological experts. These conditions cause unhealthy eating habits to develop, such as an obsession with food, body weight or body shape. In severe cases, eating disorders can have serious health consequences and may even result in death, if left untreated. Common symptoms include the severe restriction of food, food binges or purging behaviors, such as vomiting or over-exercising. The most common types of eating disorders include:

Anorexia Nervosa: This is an eating disorder that causes those suffering with it to obsess about their weight and the food they consume, often leading to low body weight.

Bulimia Nervosa: This eating disorder is characterized by vomiting after eating meals in an attempt to control one’s weight.

Binge Eating Disorder: Those with binge eating disorder frequently overeat to the point of discomfort, often as a way to deal with intense or uncomfortable feelings.

Finding Help

Whether needing intervention with substance abuse challenges, or help to manage depression and anxiety, Davis Behavioral Health is here to assist those with mental health disorders. We can provide comfort and support to those experiencing anxiety, mood, psychotic and eating disorders. We have many trained, experienced and caring mental health professionals on staff. And we offer classes, ranging from managing emotions to mindfulness, along with many others that provide the education needed to be self-sufficient in dealing with mental health challenges. Please contact us today with any questions that you may have.

Q&As for "The 5 Most Common Mental Disorders"

I often feel anxious and worried, but it doesn't seem severe. Could it still be an anxiety disorder?

While experiencing occasional anxiety is normal, excessive worry that impacts daily life could be a sign of a disorder like Generalized Anxiety Disorder (GAD). Davis Behavioral Health offers consultations to help you determine if professional support is needed. #anxietydisorders #mentalhealthcheckup

I suspect my family member might have depression, but I'm unsure how to approach them. What resources can help?

Open communication and support are crucial. The National Alliance on Mental Illness (NAMI) provides resources and guidance for families of individuals with mental health conditions. Davis Behavioral Health also offers family therapy options. #depressionawareness #supportinglovedones

I think I might have symptoms of a psychotic disorder, but I'm afraid to seek help. Is treatment available?

Seeking help is crucial for managing psychotic disorders. Early intervention with therapy and medication can significantly improve well-being. Davis Behavioral Health prioritizes a safe and supportive environment for all clients. #mentalhealthtreatment #psychoticdisorders

I'm struggling with my relationship with food, but I don't know if it qualifies as an eating disorder. What are the warning signs?

Unhealthy eating habits beyond weight concerns can indicate an eating disorder. If you’re experiencing binge eating, purging, or an obsession with food or body image, consider seeking professional help. Davis Behavioral Health has specialists in eating disorder treatment. #eatingdisorders #bodypositivity

I want to help a friend who is struggling with substance abuse. Where can I find resources and support?

Supporting someone with substance abuse can be challenging. The Substance Abuse and Mental Health Services Administration (SAMHSA) offers resources and a treatment locator. Davis Behavioral Health also provides addiction treatment programs. We have a friendly staff waiting assist you. Remember, you are not alone – 21% (50 million people) of adults are experiencing at least one mental illness. With this said, 55% of adults with a mental illness have not received any treatment. Please, contact us today.  #substanceabusehelp #supportingrecovery