Pathophysiology of Schizophrenia

1. Psychoses/ Schizophrenia
By: Dr UrmilaM. Aswar

2. Psychoses-Severe psychiatric illness with serious
distortion of thought, behaviour, capacity to recognize
reality and perception.
Schizophrenia-Schizophrenia is a particular type of psychosis
that is, a mental disorder caused by some inherent dysfunction of
the brain.
2
Fig. 1 Schizophrenia

3. Prevalence
Schizophreniaoccurswithregularfrequency
nearlyeverywhereintheworldin1%ofthe
populationandbeginsmainlyinyoungage(mostly
around16to25years).
Schizophrenialeadsto
Agroupofcharacteristicpositiveandnegativesymptoms
Deteriorationinsocial,occupational,orinterpersonal
relationships
Continuoussignsofthedisturbanceforatleast6months

4. The Primary symptom of schizophrenia :
Mania –Hyperactivity, uncontrollable thought and speech,
may be associated with violent behaviour
Depression–Sadness, guilt, physical and mental slowing,
self destructive ideation.
Bipolar -(manic-depressive)
Unipolar-(mania or depression)
4Fig. 2 symptom

5. Positive Symptoms
Hallucinations
Delusions
Disorganized thought
Perception disturbances
Inappropriate emotions
Negative Symptoms
Blunted emotions
Anhedonia
Lack of feeling
Cognition
New Learning
Memory
Mood Symptoms
Loss of motivation
Social withdrawal
Insight
Demoralization
Suicide
5

6. POSITIVE SYMPTOMS: Hallucinations
Hallucinationsarethingsapersonsees,hears,
smells,orfeelsthatnooneelsecansee,hear,
smell,orfeel.
"Voices"arethemostcommontypeofhallucinationin
schizophrenia.Thevoicesmaytalktothepersonabout
hisorherbehavior,orderthepersontodothings,or
warnthepersonofdanger.Sometimesthevoicestalkto
eachother.
Othertypesofhallucinationsincludeseeingpeopleor
objectsthatarenotthere,smellingodorsthatnoone
elsedetects,andfeelingthingslikeinvisiblefingers
touchingtheirbodieswhennooneisnear.

7. POSITIVE SYMPTOMS : Delusions
Delusionsarefalsebeliefs.Thepersonbelievesdelusionseven
afterotherpeopleprovethatthebeliefsarenottrueorlogical.
Peoplewithschizophreniacanhavedelusionsthatseembizarre,
suchasbelievingthatneighborscancontroltheirbehaviorwith
magneticwaves.
Theymayalsobelievethatpeopleontelevisionaredirecting
specialmessagestothem.
Sometimestheybelievetheyaresomeoneelse,suchasafamous
historicalfigure.
Theymayhaveparanoiddelusionsandbelievethatothersare
tryingtoharmthem,suchasbycheating,harassing,poisoning,
spyingon,orplottingagainstthemorthepeopletheycareabout.
Thesebeliefsarecalled"delusionsofpersecution."

8. Negative symptoms
Negativesymptomsareassociatedwith
disruptionstonormalemotionsandbehaviors.
Thesesymptomsincludethefollowing:
"Flataffect"(aperson'sfacedoesnotmoveorhe
orshetalksinadullormonotonousvoice)
Lackofpleasureineverydaylife-Anhedonia
Lackofabilitytobeginandsustainplanned
activities
Speakinglittle,evenwhenforcedtointeract.

9. Movement disorders
Movementdisordersmayappearas
agitatedbodymovements.Apersonwitha
movementdisordermayrepeatcertain
motionsoverandover.Intheother
extreme,apersonmaybecomecatatonic.

10. Cognitivesymptoms
Likenegativesymptoms,cognitivesymptomsmaybe
difficulttorecognizeaspartofthedisorder.Theyare
detectedwhenothertestsareperformed.
Theabilitytounderstandinformationanduseittomake
decisions.
Troubleinpayingattention
Problemswith"workingmemory"(theabilitytouse
informationimmediatelyafterlearningit).
Cognitivesymptomsoftenmakeithardtoleadanormal
lifeandearnaliving.
Theycancausegreatemotionaldistress.

11. 11

12. 12

13. CarlssonandLindqvist(1963)
Repeatedadministrationofstimulantslike
amphetaminesandcocaine,whichenhance
centraldopaminergicneurotransmission,can
causeapsychosisthatresemblesthepositive
symptomsofschizophrenia.
Stress,amajorpredisposingfactorin
schizophrenia.
13

14. Thisdisorderisfarmorecomplexthan
originallysupposed,butitinvolvesa
combinationofgeneticsand
abnormalitiesin amine
neurotransmitterfunction(especially
thatofdopamine)

15. Main categories are:
A) Typical antipsychotics
Phenothiazines (chlorpromazine, fluphenazine,
thioridazine)
Thioxanthenes (flupenthixol, clopenthixol)
Butyrophenones (haloperidol, droperidol)
B) Atypical antipsychotics (e.g. clozapine, risperidone,
sulpiride, olanzapine)
15

16. Thedifferencebetween‘typical’and‘atypical’
antipsychoticisbasedonthe
Incidenceofextrapyramidalside-effects(lessin
‘atypical’group)
Efficacyintreatment-resistantgroupofpatients
Efficacyagainstnegativesymptoms.
16