Mental Disorders: List Of The Most Common Types

A list of common mental health disorders that result in abnormal cognitive or emotional behaviors.

Mental Disorders: List Of The Most Common Types

Mental illnesses cover a spectrum of conditions, including personality disorders, emotional disorders, adjustment disorders, mood disorders, and intellectual disability.

Many of these medical conditions affect normal functioning, and those on the end of the spectrum can significantly impair mental, emotional, and physical skills.

Even though they can be incredibly isolating, mental illnesses are relatively common and need to be addressed to get the proper psychological support and treatment.


    Anxiety Disorders

    Anxiety can be a precursor to many types of mental health disorders. Therefore, suffering from anxiety can make daily life insufferable and present many symptoms, including feelings of panic, nervousness, fear, and the physical symptoms of sweating and a rapid heartbeat.

    While it’s normal to experience anxiety occasionally, an anxiety disorder goes beyond regular nervousness.

    Instead, it occurs when your anxiety interferes with your ability to function normally, often causing an overreaction when something triggers your emotions.

    Certain people may be at a higher risk than others for anxiety disorders if they have certain personality traits such as behavioral inhibition or shyness (1).

    In addition, those feeling uncomfortable with and avoiding unfamiliar people, situations, or environments are also at high risk of developing anxiety disorders.

    Stressful and traumatic events that may have occurred in early childhood or adulthood can also leave a mark. Also, having a family history of anxiety and other mental health conditions may leave you at a higher risk of anxiety disorders.

    Among the different types of anxiety disorders, the most common that you may come across include generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobias.


    Depression is a common mood disorder and mental illness that involves a persistent sensation of feeling sad and a loss of interest. It differs from fluctuations that people may regularly experience as part of their daily life (2).

    Depression may often be confused with anxiety as the two can share certain symptoms. For instance, anxiety is felt after losing a loved one or experiencing sadness after a traumatic event.

    This feeling can include positive and happy memories paired with feelings of emotional pain.

    Depression, while it makes you sad, also involves feelings of self-loathing or loss of self-esteem. Whereas grief tends to decrease over time and occurs in waves, depression is not a passing problem but an ongoing one.

    Depressive episodes can last for several weeks, months, or even years.

    When depression is not treated in time, it can lead to the risk of self-harm, suicidal thoughts, and other abnormal thoughts.

    Fortunately, this mental health issue is considered treatable. In fact, it is among the most treatable of mental disorders, with between 80 to 90% of people with depression eventually responding well to treatment, according to the American Psychiatric Association (3).

    Attention Deficit Hyperactivity Disorder (ADHD)

    ADHD stands for attention deficit hyperactivity disorder which is a medical condition. Anyone diagnosed with ADHD has differences in brain development and brain activity that affect attention, the ability to sit still, and self-control.

    ADHD is typically identified and diagnosed in children who show signs of poor concentration and hyperactivity-impulsivity. Such children generally are very inattentive, easily distracted, and find it hard to focus their attention, concentrate, and stay on task.

    Children with ADHD are also hyperactive, restless, fidgety, and become easily bored. They have a hard time sitting still, quiet, and rushing through things making careless mistakes (4).

    Bipolar Disorder

    Bipolar disorder is a mental health condition that swings between extreme mood changes, including emotional highs known as manic episodes and extreme lows bordering on depression.

    When someone diagnosed with bipolar disorder becomes depressed, they may feel extremely sad and hopeless, losing pleasure or interest in otherwise preferred activities.

    But when their mood veers to mania or hypomania, they may feel energized, euphoric, and uncharacteristically irritable. These extreme mood swings tend to easily affect energy, judgment, behavior, sleep and hamper the ability for clear thinking.

    This mental illness is a lifelong ailment, but symptoms like mood swings can be managed by following a rigorous treatment plan. For the most part, treatment is carried out with medications and psychological support or psychotherapy.

    Personality Disorder

    Personality disorders are a type of mental illness in which a person’s thinking takes on a rigid and unhealthy pattern paired with abnormal functioning and behaving.

    As a result, people with this mental illness often have trouble perceiving and relating to situations and other people. The result can be significant problems and limitations in social activities at work, school, and interpersonal relationships.

    Some of the different types of personality disorders include the following:

    • Paranoid personality disorder makes it hard for people to confide in others, including their friends and family.
    • Antisocial personality disorder is another type of personality disorder where a person demonstrates no regard for right or wrong and ignores the feelings and rights of other people. People with antisocial personality disorder tend to antagonize, manipulate, or treat others harshly.
    • Schizoid personality disorder makes it hard for a person to function well. The mental illness does not have the psychotic symptoms of schizophrenia but still makes it difficult to form close relationships with other people.
    • Histrionic personality disorder is a personality disorder where there is an overwhelming need to be acknowledged by others, and people with the disorder usually exhibit dramatic or inappropriate behavior to get noticed. Individuals with this mental health issue often have a lot of unstable emotions and a distorted self-image.

    Dissociative Disorders

    Dissociative disorders signify an uncontrolled avoidance of reality. People suffering from these disorders experience a disconnection between their identity, thoughts, consciousness, and memory.

    The dissociative disorder first presents symptoms to respond to a traumatic event such as military combat or abuse.

    However, stressful situations may also aggravate symptoms and trigger problems with everyday life and functioning. The symptoms someone experiences will vary based on the type of dissociative disorder that the individual may have.

    There are three types of dissociative disorders defined in the diagnostic and statistical manual of mental disorders, including:

    • Dissociative amnesia is where the person finds it difficult to remember important information about themselves.
    • Depersonalization disorder involves persistent feelings of depersonalization and detachment.
    • Dissociative identity disorder is previously known as multiple personality disorder. This mental health condition characterizes switching between different identities or having a split personality.

    These various identities are responsible for controlling a person’s behavior at different times.

    Dissociative identity disorder can trigger memory loss, depression, or delusion caused by past trauma. Typically, therapy helps manage behaviors and can reduce the frequency of identity switches.

    Anyone with dissociative identity disorder should have a robust support system, including family members and friends, as well as health care providers who can help manage the condition.

    Eating Disorders

    Eating disorders are serious physical and mental illnesses involving a damaging relationship with food, exercise, and body image. These disorders are complicated and can vary significantly from one person to the next.

    The most common eating disorders are anorexia nervosa, bulimia nervosa, and binge eating disorder.

    • Anorexia nervosa centers around an immense fear of weight gain or becoming fat. As a result, people suffering from this condition have abnormally low body weight and distorted weight perception.
    • Bulimia nervosa is a mental illness and eating disorder that can present severe lifetime consequences. People who struggle with this condition suffer from episodes of eating excessive amounts of food followed by compensatory behaviors such as fasting purging, or excessive exercise.
    • Binge eating disorder is the most common among eating disorders and involves the common symptoms of eating a lot of food in a relatively short period. People who struggle with this condition also lose control during the episode, paired with extreme shame and guilt later on.

    However, unlike other eating disorders, people who have binge eating disorders do not throw up food or exercise too much.

    Therefore, even though this is a severe health problem, people with this eating disorder can get better with treatment.

    Obsessive-Compulsive Disorder

    Obsessive-compulsive disorder (OCD) is a mental health issue involving unwanted thoughts and fears that cause an individual to engage in repetitious behaviors.

    For someone to be diagnosed with obsessive-compulsive disorder, the cycle of obsessions and compulsions gets in the way of important activities that the person values.

    Obsessions are thoughts, impulses, or images that occur repeatedly and feel outside of the person’s control.

    Individuals with OCD can acknowledge these thoughts as irrational but feel compelled to perform them. The desire to break free and resist gets overtaken by the fear of them being genuine.

    Typical examples of obsessions include checking multiple times to see if the stove has been turned off or whether you locked the door or not.

    On the other hand, compulsions are repetitive gestures that offer some passing relief from the anxiety triggered by obsessive thoughts.

    For the most part, compulsions are often carried out to dissipate obsessions. However, when people try not to perform compulsive acts, the obsessive thoughts may reappear even stronger.

    Common examples of compulsions include repetitive hand washing for fear of contamination, excessive cleaning of household items and other objects, arranging objects in order till they feel “right,” or asking something repeatedly to get reassurance.

    People with obsessive-compulsive personality disorder can get help with medications and psychotherapy, and most treatment plans will use a combination of the two.


    Psychotic disorders are a group of severe mental illnesses that affect the mind causing abnormal thinking and perceptions. People with psychosis lose touch with reality, with delusions and hallucinations being two of the main symptoms.

    Delusions are false beliefs, such as imagining that someone is plotting against you or that the TV is sending you secret messages.

    On the other hand, Hallucinations are false perceptions such as hearing, seeing, or feeling something that is not there.

    This mental health disorder has different types where the person’s personality is severely confused, and they lose touch with reality. When a psychotic episode occurs, the person becomes unsure about what is real and what isn’t and suffers from incoherency.

    Psychotic disorders are primarily treated by a combination of medication and therapy. The signature medications to treat psychosis includes antipsychotics that help in managing the symptoms of the condition like hallucinations and delusions.

    Psychotherapy for psychotic disorders may include individual sessions, family sessions, and social support groups.

    With proper treatment, many people diagnosed with this psychotic disorder can lead productive lives and function normally.


    Schizophrenia is a mental disorder most commonly associated with a split personality, though this is not entirely correct.

    Instead, it is a type of psychotic disorder causing people to interpret reality unusually. Schizophrenia often results in a sequence of hallucinations, delusions, and extremely disordered thinking. The resulting behavior can impair daily functioning and be highly disabling.

    People struggling with schizophrenia often withdraw from the outside world, feel confused and afraid and are at an increased risk of attempting suicide especially, during psychotic episodes, periods of depression, and in the first six months after starting treatment.

    Even though it is a lifelong chronic disorder, most people with schizophrenia do get better over time, and there are plenty of options to help manage the mental illness.

    Since this mental illness is often episodic, periods of remission are ideal times to employ self-help strategies to limit the length and frequency of any future episodes.

    With the proper support, therapy, and medication, people with schizophrenia can better manage their symptoms, function independently, and enjoy entire, rewarding lives.

    Stress-related disorders are severe psychological reactions that can develop in people following exposure to a traumatic or stressful event such as childhood neglect, physical or sexual abuse, combat, natural disaster, an accident, serious injury, or torture.

    Symptoms for stress-related disorders are broadly classified into four categories: intrusion symptoms involving involuntary, recurrent, and distressing memories, thoughts, and dreams of a traumatic event.

    Then there are avoidance symptoms that are efforts to avoid internal memories, thoughts, and feelings or external people, places, and situations reminding the person of the traumatic event.

    A third symptom is negative alterations in cognition and mood, where the person may have problems remembering important aspects of the traumatic event. They may also experience fear, shame, guilt, depression, and feelings of isolation from others.

    The fourth symptom is hyperarousal, which includes being easily startled and jumpy, irritable, angry outbursts, problems concentrating, difficulty sleeping, and self-destructive behavior.

    Even though there are different stress-related disorders, most people have heard of post-traumatic stress disorder (PTSD) that occurs after a traumatic or stressful event. Symptoms for all of the categories discussed above must be present.

    Sleep Disorders

    Common sleep disorders include insomnia, narcolepsy, sleep apnea, and restless leg syndrome.

    These conditions can affect every aspect of life, including safety, school, work performance, relationships, thinking, mental health, and even diabetes and heart disease development.

    In other words, not getting enough quality sleep can hurt the overall quality of life.

    Different sleep orders disorders that impair sleep or prevent you from getting restful sleep often result in daytimes drowsiness and other symptoms.

    This is different from not getting enough sleep. Sleep disorders can interfere with cognitive function, leading to learning disabilities in children, memory impairment in people of all ages, personality changes, and even depression.

    Sleep-deprived people often experience difficulty making decisions, have problems with performance, are irritable, and have slower reaction times.

    These disorders can be caused by genetics, medications, aging, environmental factors, and working the night shift.

    Substance-related disorders involve an individual’s excessive substance use, such as alcohol or drugs, leading to problems and health issues at work, school, or home.

    This disorder is also called substance abuse. Many people who engage in substance abuse also have accompanying depression, PTSD, or another mental illness.

    In addition, such individuals may be experiencing a chaotic or stressful lifestyle and have low self-esteem.

    Commonly used substances include opiates and other narcotics, stimulants, depressants, and marijuana. Many of these substances yield a rewarding feeling to the brain that may be so profound that people neglect normal daily activities in favor of taking the drug.

    This addictive behavior can trigger substance-induced mental disorders, which are cognitive problems that develop in individuals who otherwise do not have mental health problems before using the substances.

    Neurodegenerative Disorders

    Neurodegenerative disorders affect the body’s various parts and functions, such as movement, balance, breathing, talking, and heart function.

    Many neurodegenerative orders may be genetic, caused by a tumor or stroke, and usually worsen over time without a cure.

    Conditions like Alzheimer’s disease and Parkinson’s disease result from progressive damage to cells and nervous system connections essential for mobility coordination, strength sensation, and cognition.

    Currently, there are no therapies available to cure neurodegeneration, and medication can only alleviate symptoms to improve the patient’s quality of life.


    Mental illnesses are among the most common disorders worldwide and can both be occasional or long-lasting.

    Not every mental illness has a treatment or cure, but for those that do, treatments will involve a combination of medication and therapy to ease and better cope with symptoms.

    It is crucial to get timely treatment as many of these conditions can cause severe disruptions in everyday life, relationships, and social settings.

    However, with a consistent treatment plan and support (5), many people can successfully manage their day-to-day functioning despite their condition.