Symptoms of Schizophrenia

Schizophrenia is a diagnostic label given by a qualified healthcare professional when an individual has a certain group of symptoms consistent with the accepted criteria for diagnosing schizophrenia. The Diagnostics and Statistical Manual of Mental Disorders, published by the American Psychiatric Association, is the most commonly referenced source for diagnostic criteria.

Schizophrenia manifests in both positive symptoms (added symptoms that feature experiences or behaviors that healthy individuals do not experience) and negative symptoms (subtraction of behaviors that healthy individuals normally exhibit). For a schizophrenia diagnosis, a person must exhibit at least two of the following symptoms for at least one month and they must persist at least somewhat for six months:

  • Hallucinations
    • Seeing things that are not there (visual hallucinations)
      • Hearing things that are not there (audible hallucinations)
      • Smelling things (olfactory hallucinations)
  • Delusions
    • Beliefs that are “made up” and not founded in reality
  • Disorganized speech (Example on YouTube)
  • Disorganized behavior or catatonia
  • Negative symptoms (see below)

For a schizophrenia diagnosis, one of the two required symptoms must be hallucinations, delusions, or disorganized speech. The first four symptoms listed represent positive symptoms, and the last one (negative symptoms) are discussed below.

Negative symptoms of schizophrenia

Negative symptoms of schizophrenia involve absences of behaviors or traits that mentally healthy people normally have. There are several possibly absent behaviors, but they can be categorized into two main categories: 1) diminished expression and 2) diminished motivation and pleasure.

  • Diminished expression (aka blunted affect) involves:
    • Diminished facial expression
    • Diminished vocal inflection and variability when talking
  • Diminished motivation and pleasure involves:
    • Avolition
      • Lack of desire to do much of anything (may be misinterpreted as ‘laziness’)
    • Anhedonia
      • Inability to experience pleasure from activities that are usually enjoyable
    • Asociality
      • Diminished drive to interact with others

A person with diminished expression will usually seem less engaged in conversation because their facial expressions and voice don’t show emotion. This, along with diminished drive to interact with others leads to hampered social relationships. Hampered social relationships can lead to further isolation and deterioration of schizophrenia, so it’s important that people suffering with schizophrenia are actively assisted in finding quality care.

Schizophrenia Spectrum

There certainly is a pattern among individuals when it comes to the symptoms and etiology of schizophrenia, so diagnosis can be a helpful first step in determining why a person is experiencing symptoms of schizophrenia. However, it’s important to understand that, as with most diseases (especially mental disorders), everyone is different and there is huge variability in symptoms and level of disintegration in various categories of functioning. Mental disorders exist on a spectrum, and lines drawn between mental conditions, although helpful, are sometimes arbitrary and misleading. For example, negative symptoms of schizophrenia also overlap with symptoms of depression. The DSM diagnostic methodology is intended to help categorize symptoms for improved treatment of mental disorders, yet individualization of care is necessary.

Symptoms of Schizophrenia, Schizophreniform Disorder, and Brief Psychotic Episode

The spectrum of psychotic disorders includes schizophrenia, schizoaffective disorder, delusional disorder, schizotypal personality disorder, schizophreniform disorder, brief psychotic disorder, as well as psychosis caused by substance use or medical conditions. Schizophrenia, schizofreniform disorder, and brief psychotic episode have virtually the same symptoms (and possibly overlapping causes), but they differ primarily in how long the symptoms last. Schizophrenia is diagnosed only if symptoms persist for longer than six months. Schizophreniform disorder is diagnosed if symptoms last over one month but shorter than six months, and brief psychotic episode is diagnosed if psychotic (positive) symptoms do not last longer than one full month.

Getting a Diagnosis of Schizophrenia

There are many variables that influence whether or not someone will be diagnosed with a mental disorder. These factors are many, but depend on 1) the severity of a person’s symptoms 2) the ability of the person to get access to a diagnosing professional 3) how “standard” the person’s symptoms are compared to the diagnostic manual, and 4) the individual practices of the diagnosing health practitioner.

Medical doctors, nurse practitioners, and psychologists can diagnose mental disorders, including schizophrenia spectrum disorders. Psychiatrists (both medical and nursing) are generally best equipped to understand the vast array of variables in medical symptoms and causes of psychosis. If you suspect you have a mental disorder, you are encouraged to seek out a qualified mental health professional.

The use of medical labels, especially mental health labels (such as schizophrenia), tends to make people feel doomed to lifelong suffering or to feel marked as different or broken. This is not true. Many people are able to heal from schizophrenia when the causes of schizophrenia and psychosis are addressed.

Healing From Schizophrenia

It’s important to understand that people can likely heal from schizophrenia. Schizophrenia symptoms are caused by brain health factors that can often be reversed or diminished. Schizophrenia is a whole-body psycho-neuro-immunological disequilibrium with pronounced effects on the brain. For example, inflammation in certain areas of the brain can hamper connectivity between regions and neurotransmitter changes, resulting in the specific positive and negative symptoms mentioned above.



  • American Psychiatric Association. (2013). Schizophrenia Spectrum and Other Psychotic Disorders. In Diagnostic and statistical manual of mental disorders (5th ed.). https://doi.org/10.1176/appi.books.9780890425596.dsm02.

Negative symptoms

  • Blanchard JJ, Cohen AS. 2006. The structure of negative symptoms within schizophrenia: implications for assessment. Schizophr. Bull. 32:238–45
  • Horan WP, Kring AM, Gur RE, Reise SP, Blanchard JJ. 2011. Development and psychometric validation of the Clinical Assessment Interview for Negative Symptoms (CAINS). Schizophr. Res. 132:140–45
  • Kirkpatrick B, Fenton W, Carpenter WT, Marder SR. 2006. The NIMH-MATRICS consensus statement on negative symptoms. Schizophr. Bull. 32:296–303
  • Kring AM, Gur RE, Blanchard JJ, Horan WP, Reise SP. 2012. The Clinical Assessment Interview for Negative Symptoms (CAINS): final development and validation. Am. J. Psychiatry.
About Nicholas Hundley, MS, CNS

Nicholas Hundley is a nutritional biochemist and certified nutrition specialist. He is the main author here at MindWhale.com. He practices nutrition and can be found at NicholasHundley.com

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