A psychiatric disorder is a mental illness diagnosed by a mental health professional that greatly disturbs your thinking, moods, and/or behavior and seriously increases your risk of disability, pain, death, or loss of freedom.1
In addition, your symptoms must be more severe than expected response to an upsetting event, such as normal grief after the loss of a loved one.2
Examples of Psychiatric Disorders
A large number of psychiatric disorders have been identified.3 Chances are that, whether or not you or someone close to you has been diagnosed with a psychiatric disorder, you know something about one or more of the following examples:
- Depression
- Personality disorders
- Anxiety disorders
- Schizophrenia
- Eating disorders
- Addictive behaviors
According to the National Institute of Mental Health (NIMH), one in five adults in the U.S. has some type of mental illness. This includes conditions that can range from mild to severe.4
NIMH distinguishes between any mental illness (AMI), which represents all recognized mental health conditions, and serious mental illness (SMI), which involves a small and more severe subset of illnesses.
NIMH reports that in 2021, 5.5% (14.1 million) of U.S. adults over the age of 18 had a serious mental illness.4
Symptoms of Psychiatric Disorders
Examples of ongoing signs and symptoms of psychiatric disorders include:5
- Confused thinking
- Reduced ability to concentrate
- Deep, ongoing sadness, or feeling “down”
- Inability to manage day-to-day stress and problems
- Trouble understanding situations and other people
- Withdrawal from others and from activities you used to enjoy
- Extreme tiredness, low energy, or sleeping problems
- Strong feelings of fear, worry, or guilt
- Extreme mood changes, from highs to lows, often shifting very quickly
- Detachment from reality (delusions), paranoia (the belief that others are “out to get you,”) or hallucinations (seeing things that aren’t there)
- Marked changes in eating habits
- A change in sex drive
- Drug or alcohol abuse
- Excessive anger, hostility, and/or violence
- Suicidal thinking
If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 988 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911.
For more mental health resources, see our National Helpline Database.
A psychiatric disorder may also cause physical symptoms, such as a headache, back pain, or stomach pain.6 If you’re being evaluated for a psychiatric disorder, tell your doctor about any physical symptoms you’re having, including unexplained aches and pains.
Types of Psychiatric Disorders
Psychiatric disorders fall into one of the following main types (often called classes or categories):3
Neurodevelopmental Disorders
Neurodevelopmental disorders affect how your brain functions and can affect cognition, behavior, communication, and motor abilities.7 The many psychiatric disorders in this group usually begin in infancy or childhood, often before a child starts school. Examples include:
- Attention-deficit/hyperactivity disorder (ADHD)
- Autism spectrum disorders
- Learning disorders
Schizophrenia Spectrum and Other Psychotic Disorders
Psychotic disorders cause detachment from reality. People with these diagnoses experience delusions, hallucinations, and disorganized thinking and speech.
Schizophrenia is probably the best known of these illnesses, although detachment from reality can sometimes affect people with other psychiatric disorders.8
Bipolar and Related Disorders
This group includes disorders in which episodes of mania (periods of excessive excitement, activity, and energy) alternate with periods of depression.
There are three types of bipolar disorder:
- Bipolar I: Characterized by episodes of mania and depression
- Bipolar II: Characterized by depressive and hypomanic episodes
- Cyclothymic disorder: Marked by depressive and hypomanic symptoms that are not severe enough to be considered mood episodes
Depressive Disorders
These include disorders characterized by feelings of extreme sadness and worthlessness, along with reduced interest in previously enjoyable activities. Examples include:
- Major depressive disorder: There are also different forms of major depressive disorder, including seasonal affective disorder and postpartum depression.
- Persistent depressive disorder (PDD): This involves mild to moderate depression that lasts longer than two years.
- Premenstrual dysphoric disorder (PMDD): This is more severe than the more widely known premenstrual syndrome (PMS). PMS is not classified as a psychiatric disorder.
Anxiety Disorders
Anxiety involves focusing on bad or dangerous things that could happen and worrying fearfully and excessively about them. Anxiety disorders include:
- Generalized anxiety disorder (GAD): Causes pervasive anxiety about a wide variety of events, situations, or activities
- Panic disorder: Causes severe, frequent panic attacks
- Phobias: Extreme or irrational fears of specific things, such as heights)
Obsessive-Compulsive and Related Disorders
People with these disorders experience repeated and unwanted urges, thoughts, or images (obsessions) and feel driven to take repeated actions in response to them (compulsions).9
Examples include obsessive-compulsive disorder (OCD), hoarding disorder, and hair-pulling disorder (trichotillomania).
Trauma- and Stressor-Related Disorders
These psychiatric disorders develop during or after stressful or traumatic life events. Some of the conditions that are included in this category of psychiatric disorders include:
- Posttraumatic stress disorder (PTSD): A condition characterized by nightmares, flashbacks, hypervigilance, difficulty concentrating, and other symptoms
- Acute stress disorder: A condition that occurs after exposure to a traumatic event that causes severe anxiety for up to a month after the trauma
- Adjustment disorders: A condition marked by symptoms of anxiety, depressed mood, anger, and irritability in response to a sudden change, such as a divorce, breakup, or job loss
Dissociative Disorders
These are disorders in which a person’s sense of self is disrupted. This can affect a person’s identity and memory. Some examples of dissociative disorders include:
- Dissociative identity disorder: A condition marked by having two or more distinct personalities or identities (formerly known as multiple personality disorder)
- Dissociative amnesia: Characterized by memory loss that can be brief or long-lasting
- Depersonalization/derealization disorder: Involves symptoms of depersonalization (feeling outside of one’s body) and derealization (disconnected from reality)
Somatic Symptom and Related Disorders
A person with one of these disorders may have distressing and incapacitating physical symptoms with no clear medical cause.10 (“Somatic” means “of the body.”) Examples include:
- Illness anxiety disorder: A condition marked by an excessive worry about bodily sensations and a belief that one has or will get a serious medical condition
- Somatic symptom disorder (previously known as hypochondriasis): An excessive preoccupation with physical symptoms that create significant distress and make it difficult to function in everyday life
- Factitious disorder: Involves intentionally creating symptoms or faking symptoms of an illness
Feeding and Eating Disorders
These psychiatric disorders are disturbances related to eating. These conditions involve an excessive focus on weight or body shape that result in disordered eating patterns. These eating behaviors have a severe impact on both mental and physical health. Such conditions include:
- Anorexia nervosa: Involves food restriction that results in a very low body weight
- Bulimia nervosa: Involve binge eating followed by extreme methods to compensate for excessive calorie intake, including induced vomiting, laxative misuse, or excess exercise
- Binge eating disorder: Involves consuming large amounts of food in a short period of time
Elimination Disorders
Psychiatric disorders in this group relate to the inappropriate elimination (release) of urine or stool by accident or on purpose. Bedwetting (enuresis) is an example.
Sleep-Wake Disorders
These conditions interfere with a person’s ability to get adequate sleep, which then disrupts daytime functioning. These are severe sleep disorders, including:
- Insomnia disorder: Involves the inability to get enough sleep
- Sleep apnea: Involves breathing problems that disrupt sleep and lead to daytime sleepiness
- Restless legs syndrome: A condition that causes sensations and leg movements that make it difficult to sleep
Sexual Dysfunctions
These disorders of sexual response include such diagnoses as premature ejaculation, erectile disorder, and female orgasmic disorder.
Gender Dysphoria
These disorders stem from the distress that goes with a person’s stated desire to be a different gender. The diagnostic criteria in this group differ somewhat among children, adolescents, and adults.11
Disruptive, Impulse-Control, and Conduct Disorders
People with these disorders show symptoms of difficulty with emotional and behavioral self-control. Examples include kleptomania (repeated stealing) and intermittent explosive disorder (which causes extreme outbursts of anger).
Substance-Related and Addictive Disorders
People with these diagnoses have problems associated with excessive use of alcohol, opioids (for example, oxycodone and morphine), recreational drugs, hallucinogens, cannabis, stimulants, or tobacco. This group also includes gambling disorder.
Neurocognitive Disorders
These psychiatric disorders affect people’s ability to think and reason. The disorders in this group include delirium as well as disorders of thinking and reasoning caused by such conditions or diseases as traumatic brain injury or Alzheimer’s disease.
Personality Disorders
A personality disorder involves a lasting pattern of emotional instability and unhealthy behaviors that seriously disrupt daily living and relationships. Examples include:
- Borderline personality disorder: Characterized by intense interpersonal relationships, unstable self-image, emotional instability, and impulsivity
- Antisocial personality disorder: Involves a disregard for the right of others and the violation of rules and social norms
- Narcissistic personality disorder: Characterized by self-centeredness, lack of empathy, and an exaggerated sense of self
Paraphilic Disorders
Many sexual-interest disorders are included in this group. Examples include sexual sadism disorder, voyeuristic disorder, and pedophilic disorder.
Other Mental Disorders
This group includes psychiatric disorders that are due to other medical conditions or that don’t meet all the requirements for any of the other psychiatric disorder groups.3
When Does a Mental Health Concern Become a Psychiatric Disorder?
If you’re like most people, you’ve probably had a mental health concern from time to time, such as depression following the loss of a job. These concerns are typically time-limited, and eventually, you start to feel better.
That’s not true of a psychiatric disorder, in which your symptoms are ongoing and frequently upsetting to you and the people around you.
A psychiatric disorder also interferes with your ability to do day-to-day tasks.3