Most Common Types of Mental Illnesses

People do not always associate mental illnesses with behavior or personality disorders. The term disorder can be difficult to explain to those of us who do not suffer from them. Understanding what these types of mental illnesses are, and how they manifest themselves, is vital in helping those who suffer from them find treatment and the help they need. Understanding the difference between normal behavior and abnormal behavior, and between depression and bipolar disorder is a first step to becoming educated on the different types of mental illnesses.

There are four main categories of mental illnesses that affect millions of Americans each year. Each category is broken down into specific types of mental illnesses with varying degrees of severity, including schizophrenia, delusional disorder, post-traumatic stress disorder, bipolar disorder, and depression. Because each of these has a varying degree of symptoms and severity, it is important to recognize the signs and symptoms of each of the disorders, as well as take care of your mental health.


Schizophrenia is classified as a mental illness that can cause hallucinations, hearing voices that do not exist, and a marked personality change. Symptoms of this disorder include disorientation, paranoia, disinterest in surroundings, being unable to focus on things for an extended period of time, and the development of a variety of physical symptoms like fever, swollen feet, dry mouth, and muscles aches. If you suspect your loved one may have a case of schizophrenia, you should know that depression is also common in those with the disorder. A healthy individual will exhibit no symptoms whatsoever. However, those who suffer from depression will often exhibit signs like extreme sadness or guilt, low energy, and drastic changes in personality.

Schizophrenia is another type of mental illness. It is a brain disorder that causes hallucinations and disorganized thinking patterns. If you or a loved one displays one or more of the warning signs of schizophrenia, you should get medical attention as soon as possible. The treatment for schizophrenia is similar to that for bipolar disorder. In addition, some medications used to treat schizophrenia can also be used to treat other mood disorders, which will improve the patient’s overall mental health.

person suffering from mental illness

Eating disorders

Eating disorders are classified as a type of mental illness that affects an individual’s ability to gain weight or maintain healthy body weight. Those who are diagnosed with eating disorders will frequently engage in dangerous eating patterns, which include binge eating or purging, the consumption of large amounts of food to make a particular diet, and engaging in dangerous activities like vomiting in order to remove all food from the stomach. According to research, women are more likely to suffer from this disorder than men are. In addition, women who are diagnosed with this disorder are more likely to experience severe menstrual cycles due to the fact that they are unable to control their bodily functions like ovulation and menstruation.

Substance abuse

An individual who suffers from substance abuse is considered to be an addict. Someone who abuses alcohol or drugs is said to be suffering from substance use disorder. A person who abuses prescription medications like painkillers or antidepressants is considered to be addicted. Like with schizophrenia, a person who engages in substance abuse is likely to develop depression as a result of their substance use disorder.


According to the World Health Organization, depression is the most common mental illness experienced by Americans. Millions of Americans suffer from depression each year. According to the Centers for Disease Control and Prevention, four out of every five adults suffer from depression at some point in time. In addition, many people who suffer from depression do not seek treatment because they believe that it will go away on its own. On the other hand, untreated depression can lead to worse mental health conditions such as bipolar disorder and clinical depression.

Bipolar disorder

According to the Mayo Clinic, Bipolar disorder is a brain disorder that causes extreme changes in moods and behavior. Someone who suffers from bipolar disorder has four different phases. Each phase of bipolar disorder can cause a significant change in the lives of a person. Someone who is suffering from bipolar disorder may find themselves becoming suicidal and self-destructive. If you or your loved one is displaying any of the warning signs of any of these mental illnesses, you should seek treatment immediately.