9 Types of Mental Illnesses

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Mental Illnesses

There are many types of mental illnesses, each with different symptoms, different treatments, and different impacts on the lives of the patient and their loved ones.

On this page, you’ll learn about some of the different types of mental illnesses, including the common symptoms, how to treat them, and how you can learn to help those with these psychological disorders.

What are the 9 Mental Illnesses?

Though there are many types of mental illnesses, some of the most common, and the symptoms of each, are listed below.

Did You Know?

According to the National Institute on Mental Health, one in four adults in the United States is diagnosable with one or more psychological disorders in a given year.

Types of mental Illness

#1: Neurodevelopmental disorders (ADHD)

Often, neurodevelopmental disorders cover a wide range of problems that usually begin in infancy or early in one’s childhood typically, before they even attend grade school.

Some of the symptoms can include:

  • Inattention or hyperactivity
  • Deficits in social interaction and communication
  • Learning deficits in areas of reading, writing, and mathematics

Some of the examples of neurodevelopmental disorders include:

  • Autism spectrum disorder (ASD)
  • Attention deficit hyperactivity disorder (ADHD)
  • Learning disorders

#2: Schizophrenia spectrum and other psychotic disorders

Psychotic disorders are serious illnesses that make it hard for someone to think clearly, make good judgements, respond emotionally, and communicate effectively, among other effects.

Some of the common symptoms are:

  • Delusions
  • Hallucinations
  • Disorganized thinking and speech

Some of the types of psychotic disorders are:

  • Schizophrenia
  • Delusional disorder
  • Short psychotic disorder

Bipolar disorder, otherwise known as manic-depressive illness, is a brain disorder that causes unusual shifts in mood, energy, activity levels, and the ability to carry out day-to-day tasks.

Some of the symptoms can include:

  • Mania or hypomania, such as periods of excessive activity and energy
  • Major depressive episodes
  • Mood swings

Some of the types of bipolar disorders are:

  • Anxiety disorders
  • Some impulse control disorders
  • Personality disorders

#4: Depressive disorders

Also known as clinical depression, depressive disorders come in the sense of constant hopelessness and despair. This may make it difficult to eat, sleep, work, and enjoy friends and activities.

Some of the symptoms may include:

  • Fatigue or loss of energy almost every day
  • Insomnia or hypersomnia (excessive sleeping) almost every day
  • Impaired concentration, indecisiveness

Some of the common depressive disorders include:

  • Clinical depression
  • Premenstrual dysphoric disorder
  • Major depressive disorder

While it doesn’t appear that there is a single cause, some people seem to be more predisposed to developing substance-use disorders than others.

According to the DSM-5, diagnosis of a substance abuse disorder is based on evidence of impaired control, social impairment, risky use, and pharmacological criteria.

Some of the symptoms include:

  • Craving the substance or activity
  • Developing a tolerance, which requires more of the substance
  • Experiencing withdrawal symptoms after stopping

Some of the types of substance-related disorders are:

  • Alcohol use disorder (AUD)
  • Cannabis use disorder
  • Gambling disorder

Did You Know?

Recent estimates indicate that nearly 21 million adults in the United States have a substance-related addictive disorder.

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#6: Obsessive-compulsive disorders

Formerly classified as a type of anxiety disorder, obsessive-compulsive disorder is now regarded as a unique condition that traps people in endless cycles of thoughts and behaviors.

Some of the symptoms include:

  • Having things symmetrical or in a perfect order
  • Excessive cleaning and / or handwashing
  • Usually spends at least one hour a day on these thoughts or behaviors

Some of the types of these disorders include:

  • Obsessive-compulsive disorder
  • Hoarding disorder
  • Hairpulling disorder (trichotillomania)

Usually, trauma- and stressor-related disorders occur in people after they have experienced a shocking, scary, or dangerous event.

This also includes those who experience recurring disturbing events, such as first aid responders. It can even include those who experience a sudden, unexpected death of a loved one.

To be diagnosed with PTSD, one of the types of stressor related disorders, an adult must experience all of the following for at least one month:

  • One re-experiencing symptom
  • One avoidance symptom
  • Two arousal and reactivity symptoms
  • Two cognition and mood symptoms

Some of the types are:

  • Post-traumatic stress syndrome
  • Acute stress disorder
  • Adjustment disorders

#8: Personality disorders

Because those who suffer from a personality disorder have trouble perceiving and relating to situations and people, they typically suffer from significant problems and limitations in relationships, social activities, work, and school.

Some of the symptoms are:

  • Persistent lying, stealing, using aliases, conning others
  • Unstable and intense relationships
  • Failure to recognize others’ needs and feelings

Some of the types of personality disorders are:

  • Borderline personality disorder
  • Antisocial personality disorder
  • Narcissistic personality disorder

#9: Anxiety disorders

While we all experience anxiety at some point in our lives, those with an anxiety disorder face this excessive worry or fear every day. These symptoms can get worse over time and interfere with daily activities.

Some of the symptoms include:

  • Restlessness
  • Muscle tension
  • Sudden and repeated attacks of intense fear

Some of the types of anxiety disorder include:

  • Generalized anxiety disorder
  • Panic disorder
  • Phobias

What Is the DSM-5?

The Diagnostic and Statistical Manual of Mental Disorders (DSM) is the handbook used by health care professionals in the United States and across much of the world as the authoritative guide to the diagnosis of mental disorders. It’s now in its 5th Edition.

Treatments for Mental Illnesses

When it comes to treating mental illnesses, there is no one-size fits all approach. In fact, even people with the same diagnosis will have different experiences, needs, goals, and objectives for treatments.

Some research has shown that the experience of care and outcomes are improved when patients are directly involved in designing their own treatment plan, including defining recovery and wellness goals.

Usually, treatments include a combination of people, medications, and other resources. Of course, it’s best to discuss specific plans with a doctor, psychologist, psychiatrist, or licensed counselor.

Treatment team for the types of mental illnesses

Sometimes, if the patient has a mild mental illness with well-controlled symptoms, treatment from one health care provider may be sufficient.

However, often, it a team approach is better, especially for cases of severe mental illnesses. Your treatment team may include:

  • Primary care doctor
  • Family members
  • Social worker
  • Psychiatrist
  • Psychotherapist, such as a psychologist or licensed counselor
  • Pharmacist


While it’s important to remember that medications cannot cure mental illnesses, they may be able to control symptoms. Plus, medications may be able to help make other treatments, such as psychotherapy, more effective.

The most commonly used classes of prescription psychiatric medications include:

  • Antidepressants
  • Anti-anxiety
  • Mood-stabilizing
  • Antipsychotic

Did You Know?

Depression is the leading cause of disability worldwide.

How Do Psychologists Diagnose and Treat Mental Disorders?

At one point or another, everyone experiences tough times and the emotions that go along with them. However, if the negative feelings, such as depression, anxiousness, or wanting to avoid people, don’t go away, it’s important to take action.

Research has shown that getting help early may be able to prevent symptoms from getting worse and making a full recovery more likely.

The best way for your family doctor, psychologist, or psychiatrist to diagnose a mental illness is through a mental assessment, which can include any combination of the following:

  • Physical exam
  • Lab tests
  • Mental health history
  • Personal history
  • Mental evaluation
  • Cognitive evaluation

What’s the Difference Between a Mental Illness and Mental Health?

Increasingly, mental illness and mental health are being used interchangeably, even though they do not mean the same thing.

Mental health, or your mental well-being, consists of your:

  • Emotions
  • Thoughts
  • Feelings
  • Social connections
  • Ability to solve problems
  • Understanding of the world around us

On the other hand, mental illness affects the way people think, behave, and interact with others. There are many types of mental illnesses, each with different symptoms and different treatments.

Help Those with Mental Disorders

Are you interested in helping those with mental illnesses? One of the best ways is to earn a graduate degree in psychology, which normally requires that you choose a concentration, such as clinical psychology, applied behavior, or social and personality.

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