Schizophrenia is a chronic and severe mental disorder that affects how a person thinks, feels, and behaves. People with schizophrenia may seem like they have lost touch with reality. Although schizophrenia is not as common as other mental disorders, the symptoms can be very disabling.
Signs and Symptoms
Symptoms of schizophrenia usually start between ages 16 and 30. In rare cases, children have schizophrenia too. The symptoms of schizophrenia fall into three categories: positive, negative, and cognitive.
“Positive” symptoms are psychotic behaviors not generally seen in healthy people. People with positive symptoms may “lose touch” with some aspects of reality. Symptoms include:
Thought disorders (unusual or dysfunctional ways of thinking)
Movement disorders (agitated body movements)
“Negative” symptoms are associated with disruptions to normal emotions and behaviors. Symptoms include:
“Flat affect” (reduced expression of emotions via facial expression or voice tone)
Reduced feelings of pleasure in everyday life
Difficulty beginning and sustaining activities
For some patients, the cognitive symptoms of schizophrenia are subtle, but for others, they are more severe and patients may notice changes in their memory or other aspects of thinking. Symptoms include:
Poor “executive functioning” (the ability to understand information and use it to make decisions)
Trouble focusing or paying attention
Problems with “working memory” (the ability to use information immediately after learning it)
There are several factors that contribute to the risk of developing schizophrenia.
Genes and environment: Scientists have long known that schizophrenia sometimes runs in families. However, there are many people who have schizophrenia who don’t have a family member with the disorder and conversely, many people with one or more family members with the disorder who do not develop it themselves.
Scientists believe that many different genes may increase the risk of schizophrenia, but that no single gene causes the disorder by itself. It is not yet possible to use genetic information to predict who will develop schizophrenia.
Scientists also think that interactions between genes and aspects of the individual’s environment are necessary for schizophrenia to develop. Environmental factors may involve:
Exposure to viruses
Malnutrition before birth
Problems during birth
Different brain chemistry and structure: Scientists think that an imbalance in the complex, interrelated chemical reactions of the brain involving the neurotransmitters (substances that brain cells use to communicate with each other) dopamine and glutamate, and possibly others, plays a role in schizophrenia.
Some experts also think problems during brain development before birth may lead to faulty connections. The brain also undergoes major changes during puberty, and these changes could trigger psychotic symptoms in people who are vulnerable due to genetics or brain differences.
Comorbid substance abuse and mental illness
Drugs and Alcohol
Did you know that addiction to drugs or alcohol is a mental illness? Substance use disorder changes normal desires and priorities. It changes normal behaviors and interferes with the ability to work, go to school, and to have good relationships with friends and family. In 2014, 20.2 million adults in the U.S. had a substance use disorder and 7.9 million had both a substance use disorder and another mental illness. More than half of the people with both a substance use disorder and another mental illness were men (4.1 million). Having two illnesses at the same time is known as “comorbidity” and it can make treating each disorder more difficult.
What Is Comorbidity?
The term “comorbidity” describes two or more disorders or illnesses occurring in the same person. They can occur at the same time or one after the other. Comorbidity also implies interactions between the illnesses that can worsen the course of both.
Is Drug Addiction a Mental Illness?
Yes. Addiction changes the brain in fundamental ways, disturbing a person’s normal hierarchy of needs and desires and substituting new priorities connected with procuring and using the drug. The resulting compulsive behaviors that weaken the ability to control impulses, despite the negative consequences, are similar to hallmarks of other mental illnesses.
How Common Are Comorbid Drug Addiction and Other Mental Illnesses?
Many people who are addicted to drugs are also diagnosed with other mental disorders and vice versa. For example, compared with the general population, people addicted to drugs are roughly twice as likely to suffer from mood and anxiety disorders, with the reverse also true.
Why Do These Disorders Often Co-occur?
Although drug use disorders commonly occur with other mental illnesses, this does not mean that one caused the other, even if one appeared first. In fact, establishing which came first or why can be difficult. However, research suggests the following possibilities for this common co-occurrence:
Drug abuse may bring about symptoms of another mental illness. Increased risk of psychosis in vulnerable marijuana users suggests this possibility.
Mental disorders can lead to drug abuse, possibly as a means of “self-medication.” Patients suffering from anxiety or depression may rely on alcohol, tobacco, and other drugs to temporarily alleviate their symptoms.