Schizophrenia​

Study Guide ​

 

Definition: a mental disorder that includes a broad range of perceptual, cognitive and behavioral disturbances.

  • Brief Psychotic disorder: >1 day and < 1 month 

  • Schizopheniform disorder: >1 month and < 6 month 

  • Schizophrenia: > 6 months 

  • Schizoaffective disorder: Schizophrenia + major affective disorder

 

Epidemiology: 

  • Point prevalence of the condition is 0.5-1% throughout the world

  • The peak age of onset is the early 20s 

 

 

Causes: 

  • Genetic and multiple environmental factors that affect brain development.

  • Schizophrenia has a heritability of about 60%. (47% in monozygotic twins, 12% in dizygotic twins)

  • Early use of Cannabis may be a risk factor.

  • Dopamine excess (D2) in mesolimbic pathways is the oldest and most widely accepted neurochemical hypothesis.

 

Pathophysiology:  

  • Anatomical abnormalities:

    • Ventricular enlargement: mainly with negative symptoms.

    • Reduced brain size.

    • Reduced connectivity between the frontal and temporal lobes.

  • Neurotransmitter abnormalities:

    • ↑dopamine, serotonin, and alpha-adrenergic activity.

    • ↓GABA and glutamate activity.

    • Mainly seen in the mediodorsal thalamic nucleus in the prefrontal cortex. 

 

Signs and Symptoms: 

  • Auditory hallucinations in the third person, and/or voices commenting on their behavior 

  • Thought withdrawal, insertion and broadcast 

  • Primary delusion (arising out of nothing)

  • Delusional perception

  • Somatic passivity and feelings – patients believe that thoughts, feelings or acts are controlled by others 

 

 

 

Positive symptoms 
  • Disorganized speech/thoughts.

  • Disorganized behaviors.

  • Catatonic behavior.

  • Hallucinations

  • Delusions 

Negative Symptoms 
  • Blunted affect. 

  • Poverty of speech.

  • Poverty of movement.

  • Poverty of socializing.

  • Poverty of joy.

  • Poverty of motivation.

Other symptoms of acute schizophrenia include behavioral disturbances, other hallucinations, secondary (usually persecutory) delusions and blunting of mood. 

Types:  

  • Paranoid: very dangerous to self and others: aggressive, fearful, and uncooperative. (better prognosis)

  • Disorganized (poor prognosis)

  • Residual: no positive symptoms, mostly negative

  • Catatonic: psychomotor disturbance.

  • Undifferentiated: positive symptoms.

Diagnosis: 

  • A helpful diagnostic point is that altered consciousness and disturbances of memory do not occur in schizophrenia. 

  • Urine Drug screen to exclude cocaine and amphetamine.

DSM-5 Criteria (at least 2 of the following) continuous for more than 6 months:  

  • Delusions.   

  • Hallucinations.

  • Negative symptoms. 

  • Disorganized or catatonic behavior.

  • Disorganized Speech.

Treatment:

Side effects:

  • Corneal deposits.

  • Retinal deposits.

  • Extrapyramidal symptoms + hyperprolactinaemia 

First Generation :(Typical Antipsychotics)
      Drugs:​ ​
  • Chlorpromazine 

  • Thioridazine

  • Haloperidol 

 
 
 
 
 
(Common SE: sedation and extrapyramidal symptoms)

Blocking D1 & D2 receptors to control the positive symptoms only. 

Side effects:

  • Agranulocytosis, and seizures.

  • Mainly weight gain.

  • Prolonged QT. 

Second Generation (Atypical Antipsychotics) (Common SE: weight gain)
      Drugs:​ ​
  • Clozapine

  • Olanzapine

  • Ziprasidone​​

 
 
 
 
 
(Common SE: weight gain) 

Blocking of D2 and 5-HT2A receptors to control both positive and negative symptoms. 

Prognosis:
o 10% of patients will commit successful suicide.

References:

  1. Fischer, Conrad. Master The Boards. Print.

  2. Kumar, Parveen J, and Michael L Clark. Kumar & Clark's Clinical Medicine. Print.

  3. Merck Manuals Professional Edition,. 'Schizophrenia - Psychiatric Disorders'. N.p., 2015. Web. 4 Nov. 2015.

  4. Marwick, Katie, Steven Birrell, and Julius Bourke. Psychiatry. Edinburgh: Elsevier, 2013. Print. x

First author:Abdullah AlAsaad  


Second author : Lama Al Luhidan 

Reviewers: Roaa Amer
                  Nada Al Hassan

Web Publisher : Adel Yasky 

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