Schizophrenia & Other Disorders of Psychosis

Psychosis = disorganized thoughts and distorted perception of reality. Psychotic individuals will usually have a loss of function and a lack of insight (they don’t realize their perception of reality is distorted).

  • Hallucinations – hearing, seeing, feeling, tasting or smelling something that isn’t really there. This sensation has no external stimuli. Due to the lack of insight these individuals think that what they perceive is real. Schizophrenia is usually associated with auditory hallucinations where the individual hears voices. Tactile Hallucinations like the sensation of bugs crawling on their skin is usually related to street drugs. Olfactory (smell) hallucinations are more commonly seen in the aura before seizures.
  • Delusions – strongly held beliefs that are not based on fact. Due to the lack of insight trying to convince a psychotic person that their delusions are false is almost impossible no matter of how much evidence you present. Delusions of Persecution are the most common type and involve paranoia. These individuals think others are “out to get them” and are trying to follow them, spy on them, poison them, steal from them or otherwise harm them. Delusions of Grandeur are when an individual believes that have special powers, talents or intellect. They may think they are famous, have supernatural abilities or have religious prominence. Other common themes in delusion are guilt, thought control, thought broadcasting (belief that others can hear your thoughts) and ideas of reference (belief that people on TV/radio/print media are talking about you).
  • Disorganized Speech (Thought Disorder) is random, incoherent speech that may involve repeating phrases or words that sound similar. The patient likely is not aware that their speech makes no sense to others. This is sometimes referred to as “Word Salad.”
  • Catatonia –motor hyperactivity with repetitive purposeless motions or motor hypoactivity that leads to complete motor immobility & waxy flexibility (you can move the patient into an odd position and they will stay in that position for hours). It can include a complete disconnect from reality. This should not be confused with Cataplexy which is a type of narcolepsy where people have motor immobility while remaining completely aware of their surroundings.

Catatonia Waxy Flexibility


In the previous video in the Psychiatry section we covered mood disorders. There we briefly discussed Mania with psychosis and depression with psychosis. The key difference between schizophrenia and a mood disorder with psychosis is that the psychosis in mood disorders is “Mood Congruent.” This means that the psychosis is only present during mood “episodes” and that the psychosis is in line with their mood. So a manic individual may have delusions of grandeur and a depressed person might have delusions of guilt.


Schizophrenia – a chronic progressive psychiatric condition characterized by psychosis and an abnormal interpretation of reality. They have a difficult time functioning in society due to progressive loss of function. Symptoms are categorized into 2 groups, Negative and Positive Symptoms.

  • Positive symptoms = behaviors or sensations that are not normally present. These symptoms are may be related to an excess of dopamine. Examples include hallucinations, delusions, catatonia & disorganized speech/behavior
  • Negative symptoms = The absence of normal behavior. Examples include a lack of initiative, diminished speech, disheveled appearance & flat affect.


There used to be specific subtypes of Schizophrenia based on what types of psychosis were predominate, but the difference between those types was low yield and in the most recent version of the DSM those subtypes have been removed.


To make a diagnosis of schizophrenia you need to rule out other potential causes of psychosis. Street drugs like cocaine or hallucinogens as well as prescription medications like corticosteroids or antiparkinsonian drugs can cause psychosis. General medical conditions such as stroke, delirium, and dementia also need to be ruled out from the differential diagnosis. Thankfully these intricacies are a bit beyond the scope of the USMLE Step 1 exam. If the question stem has a clear picture of psychosis you can safely choose Schizophrenia unless there is a big hint like recent use of cocaine.


The duration of Schizophrenia Symptoms:

  • Brief Psychotic Disorder = < 1 mo
  • Schizophreniform = 1-6 months
  • Schizophrenia = > 6 months


Schizoaffective Disorder – a mood disorder in the presence of a psychotic disorder. It can be thought of as Schizophrenia plus Major Depressive Disorder or Bipolar Disorder. Differentiating between schizoaffective disorder and a mood disorder that has psychotic features can be challenging. Thankfully this is a bit beyond the scope of the exam, but the key is what symptoms are predominant. In Schizoaffective disorder psychosis is the primary symptom and changes in affect only occasionally occur during psychotic episodes. These individuals will not be depressed or manic in the absence of psychosis. Alternatively, a Bipolar person will primarily have mood symptoms and will only occasionally have psychosis during a depressive or manic episode. They will not have psychotic symptoms when they are in a euthymic state (or neutral mood).


Delusional Disorder – a disorder characterized by a delusion and the lack of other psychotic symptoms (no hallucinations or thought disorder). These individuals do not have loss of function and may appear normal most of the time. Unlike the delusions in Schizophrenia, the delusion in Delusional Disorder are usually fixed and non-bizarre. So while the delusion is not based on reality it is at least plausible. A bizarre delusion would be something like “aliens abducted me” while a non-bizarre delusion would be something like “my neighbor is trying to kill me” which could potentially occur in real life.


The prefix Schizo means “split”. This has unfortunately led to a lot of confusion in the media and general public. Many believe Schizophrenia is a type of split personality disorder (AKA Dissociative Identity Disorder) when the two disorders are not related. The split prefix actually refers to the gap between a schizophrenic person and reality. This prefix applies to many of the disorders within the “Schizophrenia Spectrum and Other Psychotic Disorders” category, which is a new title added to the latest version of the DSM. Schizoid Personality Disorder, Schizotypal Personality Disorder, Schizophrenia and Schizoaffective Disorder all have a detachment from reality and/or others. These disorders also share features like blunted affect. Individuals with a family history of schizophrenia are more likely to be schizoid, schizotypal or schizoaffective.


As a memory mnemonic you can think of there being a continuum from Schizoid to Schizoaffective where each successive step has most of the characteristics of the previous step plus additional symptoms. The way I remember this is that as the number of letters increases so do the number of symptoms.

The Schizophrenia Spectrum - Schizoid, Schizotypal & Schizoaffective

The “Schizo Spectrum”:

  • Schizoid = very introverted and voluntarily withdraws from social interactions
  • Schizotypal = Schizoid symptoms + magical thinking & odd behavior
  • Schizophrenia = Schizotypal + Psychosis
  • Schizoaffective = Schizophrenia + Mood Disorder

* Schizophreniform (schizophrenia symptoms for 1-6 months duration) unfortunately does not fit into this mnemonic)


Picture Used:

Derivative of “Flexibilitas cerea” available at via Public Domain


2 thoughts on “Schizophrenia & Other Disorders of Psychosis”

  1. Hello my name is Renee and I am studying for my License as a social worker and I find this to be very help way to memorize this information. Thanks so much I have watch all the videos on the you site very helpful.

  2. Hey man just wanted to let you know that this was SUPER helpful. Step 1 in a month. Thanks for what you do. Will surely donate once this test is behind me.

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