Schizophrenia – Diagnosis, Symptoms and Treatment

Medically Reviewed by Dr. Po-Chang Hsu, MD, MS

Medically reviewed by Dr. Po-Chang Hsu, MD, MS

Medical Professional

Updated - January 25, 2021

Dr. Po-Chang Hsu is a medical doctor from Tufts University in Boston, Massachusetts, interested in pediatrics and neonatology.

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What is Schizophrenia?

Schizophrenia is a psychiatric disorder characterized by hallucinations, delusions, disorganized thought, cognitive impairment, and mood symptoms.  Hallucinations may include hearing voices (auditory hallucinations) or seeing things (visual hallucinations) that are not present.  Patients also often have “negative” findings such as decreased energy, flat affect, and a lack of interest.  These symptoms must typically be present for at least 6 months and not be better explained by another medical or psychiatric disorder.

Common risk factors for the disease include immigration and living in an urban area.  The condition is a common form of disability as patients lose their ability to make rational decisions, socially function, work, or adequately care for themselves.  Schizophrenia frequently coexists with other psychiatric diagnoses, including depression, anxiety, and substance abuse disorder.  The risk for suicide is significantly increased in affected individuals.

What Causes Schizophrenia?

Schizophrenia is caused by an interplay of genetic and environmental factors.  Family and twin studies demonstrate a vital genetic component to the condition.  Researchers have also discovered that the disease is associated with neurotransmitter abnormalities in the brain, including dopamine, glutamate, GABA, and acetylcholine.

Common risk factors for the condition include:

  •         Living in a metropolitan area
  •         Immigration to another country
  •         Complications during labor & delivery – bleeding, preterm labor
  •         Birth during winter and early spring seasons
  •         Having an older father at conception

How Common is Schizophrenia?

Schizophrenia is a relatively common disorder that is typically managed by a psychiatry specialist.  Individuals with the disease often require multidisciplinary teams (including a social worker) for their proper care.

Schizophrenia has a worldwide prevalence of approximately 1%.  Incidence of the disease is about 1.5 per 10,000 people per year.  Patients are typically diagnosed during adolescence.  The condition appears to be more common in men than women – men may also have a worse prognosis than women.  Individuals with schizophrenia frequently have coexisting psychiatric disorders such as depression, anxiety, and substance use disorders.

Signs and Symptoms

Symptoms of schizophrenia are often categorized into positive and negative symptoms.  Positive symptoms typically include:

  •         Hallucinations
  •         Disorganization
  •         Delusions

Hallucinations are perceived sensations that have no external source.  These often include auditory hallucinations (e.g., hearing voices) and visual hallucinations (e.g., seeing objects).  Delusions are fixed, false beliefs that may include paranoia or grandiosity.  Disorganized thought is often characterized as rushing from one topic to the next in a disorganized fashion (tangential speech) or speaking incomprehensible sentences (word salad).

Negative symptoms often include:

  •         Flat affect
  •         Lack of speech
  •         Lack of interest
  •         Low energy

Besides positive and negative symptoms, patients often develop cognitive impairment and mood abnormalities such as anxiety and depression.


The diagnosis of schizophrenia is suggested based on the presence of 2 of the following features for 6 or more months:

  •         Delusions
  •         Disorganized speech
  •         Disorganized or catatonic behavior
  •         Hallucinations
  •         Negative symptoms

Symptoms must affect the social or occupational function and not be explained by another medical or psychiatric diagnosis.

Your doctor may order routine laboratory tests to rule out metabolic or neurologic disorders.  Commonly ordered blood tests include a CMP (comprehensive metabolic panel), CBC (complete blood cell count), thyroid function tests (TSH, free T4), and RPR (syphilis testing).  They will also usually check your cholesterol levels and screen for diabetes - antipsychotic medications commonly used to treat schizophrenia can increase the risk of weight gain, diabetes, and elevated cholesterol.

Antipsychotics may also cause an electrical abnormality in the heart called QT prolongation.  This can lead to life-threatening cardiac arrhythmias such as ventricular fibrillation.  Therefore, your doctor will frequently order an EKG (electrocardiogram) to evaluate any abnormalities before starting you on antipsychotic drugs.

Schizophrenia Medication

Schizophrenia is usually treated with antipsychotic medications.  These drugs typically work by blocking dopamine receptors in the brain.  First-generation antipsychotics include:

Newer generation atypical antipsychotics commonly include:

Many of these medications come in standard oral formulations, rapid dissolving tablets, or intramuscular injections.  There are also long-acting injectable formulations such as fluphenazine decanoate that are often reserved for patients with schizophrenia who are non-compliant with prescribed therapy.

Clozaril (Clozapine) is typically reserved for patients with refractory symptoms and requires regular blood tests as it may cause a life-threatening decrease in white blood cell count.  Zyprexa (Olanzapine) is generally used as a second-line medication due to its potential side effects such as weight gain and diabetes.  Patients on antipsychotic therapy are usually monitored closely by their doctor for side effects such as movement disorder and tardive dyskinesia.


  1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), American Psychiatric Association, Arlington, VA 2013. -
  2. Buchanan RW, Kreyenbuhl J, Kelly DL, et al. The 2009 schizophrenia PORT psychopharmacological treatment recommendations and summary statements. Schizophr Bull 2010; 36:71. -

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.