Many factors have been linked to schizophrenia, including genetics and environmental factors, but it is not yet known exactly what causes it. Worldwide, it is estimated that around 1% of adults live with schizophrenia.

Symptoms usually start to develop during young adulthood, between late adolescence and a person’s early thirties. Schizophrenia tends to emerge slightly earlier in men than in women.

Schizophrenia diagnosis is based on clinical features assessed by a mental health provider, using criteria in the “Diagnostic and Statistical Manual of Mental Disorders” (DSM–5). For a diagnosis of schizophrenia, the symptoms should not be caused by the effects of substance abuse, medication, or another medical condition,

A diagnosis of schizophrenia requires two or more of the following symptoms to be exhibited for a significant portion of time during a six-month period:

Delusions Hallucinations Disorganized speech (e. g someone frequently derails from their train of thought or is incoherent) Grossly disorganized or catatonic behavior Diminished emotional expression or avolition, also called negative symptoms

At least one of the symptoms involved in the diagnosis must be among the first three—delusions, hallucinations, or disorganized speech, with significant problems with functioning in areas such as self-care, relationships, and/or at work. 

Positive Symptoms

Positive symptoms are characterized by altered perceptions, as well as abnormal thinking and disorganized behaviors. While they are referred to as positive, the term is not used to describe ‘good’ symptoms, but rather the development of symptoms that a person without schizophrenia would not experience.

The main positive symptoms of schizophrenia are:

Hallucinations: Experiences of things that are not real. For example, seeing or hearing things, such as voices, that are not there. While these types of hallucinations are the most common, a person can hallucinate a touch, taste, or smell as well.  Delusions: Firmly held beliefs that are not supported by objective facts. For example, they may display paranoia, the fear that others are out to get them, or believe those on television or radio are talking directly to them.  Disorganized thoughts and speech: Ways of thinking or speaking that seem odd or illogical. This can involve stopping talking in the middle of a sentence or thought (also called thought blocking) or speaking incoherently, including making up words that have no meaning (also referred to as “word salad”).

Negative Symptoms

Negative symptoms are characterized by social withdrawal, as well as difficulty functioning normally and expressing emotions. They are not referred to as negative because they are ‘bad,’ but rather because they refer to the absence of normal emotional responses or thought processes.

The main negative symptoms of schizophrenia are:

Alogia: A reduction in the amount a person speaks and a loss of spontaneity in the conversations they holdAnhedonia: A reduced ability to experience pleasant emotionsAsociality: Decreased interest in, or motivation for, forming close relationships with others. Rather than referring to a person’s behavior, asociality refers mainly to how much someone values and desires social interaction and close social bonds.  Avolition: A decrease in a person’s desire and interest in goal-directed activitiesBlunted affect: A reduction in a person’s expression of emotion, including facial expressions, such as smiles or frowns, or talking in a flat voice

Cognitive Symptoms

Most people who have schizophrenia experience some cognitive deficits, and have challenges in the way they think and understand the world around them. For example, cognitive symptoms can include difficulty processing information or trouble paying attention.

The cognitive symptoms are typically among the earliest signs of schizophrenia, often preceding the onset of the first severe episode. Cognitive symptoms can be difficult to diagnose early in the course of the illness. While they are core features of schizophrenia, they are not considered core symptoms in the same way that positive and negative symptoms are.

Examples of cognitive symptoms include: 

Neurocognitive impairment: Impairment of memory, attention, verbal learning, reasoning, planning, abstract thinking, and problem-solvingImpaired sensory perception: Impaired discrimination of tone and/or an inability to accurately perceive visual stimuliSocial cognition: Difficulties correctly processing information from social clues. For example, a person with schizophrenia may struggle with accurately identifying and responding to facial expressions.

Symptoms in Teens and Adolescents

In rare cases, schizophrenia can occur in children. It is estimated that approximately 1 in 40,000 may have childhood-onset schizophrenia (COS), with the illness diagnosed prior to the age of 13.

The symptoms of schizophrenia in children are often hard to spot because many of the features of the condition are common during normal childhood development. Warning signs of early-onset schizophrenia (EOS) and childhood-onset schizophrenia (COS) are often nonspecific and include emotional, behavioral, and cognitive psychopathology.

Complications

Individuals with schizophrenia and other psychotic disorders are over-represented in the homeless population.

It is not uncommon for people with schizophrenia to have substance use disorder. Nearly half of patients with schizophrenia exhibit either alcohol or illicit drug dependence during their lifetime. 

Substance abuse, in general, is linked to poor outcomes in terms of recovery. It can also increase the risk of suicide, trauma, and homelessness, as well as the risk of developing other mental illnesses.

Substance abuse has also been linked to the increased risk of violence among people with schizophrenia. This does not mean that a person with schizophrenia will be violent. There is considerable uncertainty over the link between schizophrenia itself and increased risk of violent behavior.

From a medical standpoint, schizophrenia has been linked with an increased risk of developing metabolic syndrome. This group of conditions, which includes obesity, hypertension, and insulin resistance, increase the risk of type 2 diabetes and cardiovascular disease. 

People with schizophrenia have a life expectancy 20% lower than the general population, mainly due to physical illness.

A Word From Verywell

Schizophrenia usually develops gradually, sometimes with warning signs and cognitive deficits developing before the first severe episode.

The early warning signs include:

Social withdrawalDecline in self-care or personal hygieneNew difficulty in thinking clearly or concentratingA worrying drop in grades or job performanceSuspiciousness of or uneasiness around other peopleDifficulty telling reality from fantasy

These changes, by themselves, are not concerning. However, if you, or someone you love, experience a number of these changes in behavior, you should contact a mental health professional. Early diagnosis and treatment of schizophrenia increase the chance of successful recovery. 

If you or your loved one is thinking or talking about harming themselves, contact someone who can help right away. You can call the toll-free, 24-hour National Suicide Prevention Lifeline (Lifeline) (800-237-8255).

If you require immediate emergency care, call 911 for emergency services or go to the nearest emergency room.