Schizophrenia is a mental disorder characterized by a breakdown of thought processes and by poor emotional responsiveness. It most commonly features auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social or occupational dysfunction. The onset of symptoms typically occurs in young adulthood, with a global lifetime prevalence of about 0.3–0.7%. Diagnosis is based on observed behavior and the patient’s reported experiences.

Genetics, early environment, neurobiology, and psychological and social processes appear to be important contributory factors; some recreational and prescription drugs appear to cause or worsen symptoms. Current research is focused on the role of neurobiology, although no single isolated organic cause has been found. The many possible combinations of symptoms have triggered debate about whether the diagnosis represents a single disorder or a number of discrete syndromes. Despite the etymology of the term from the Greek roots skhizein and phren, phren- (φρ?ν, φρεν-; “mind”), schizophrenia does not imply a “split personality”, or “multiple personality disorder” (which is known these days as dissociative identity disorder)—a condition with which it is often confused in public perception. Rather, the term means a “splitting of mental functions”, because of the symptomatic presentation of the illness.

Causes :

A combination of genetic and environmental factors play a role in the development of schizophrenia. People with a family history of schizophrenia who suffer a transient psychosis have a 20–40% chance of being diagnosed one year later.


Estimates of heritability vary because of the difficulty in separating the effects of genetics and the environment.The greatest risk for developing schizophrenia is having a first-degree relative with the disease (risk is 6.5%); more than 40% of monozygotic twins of those with schizophrenia are also affected. It is likely that many genes are involved, each of small effect and unknown transmission and expression. Many possible candidates have been proposed, including specific copy number variations, NOTCH4, and histone protein loci. A number of genome-wide associations such as zinc finger protein 804A have also been linked. There appears to be significant overlap in the genetics of schizophrenia and bipolar disorder.
Assuming a hereditary basis, one question from evolutionary psychology is why genes that increase the likelihood of psychosis evolved, assuming the condition would have been maladaptive from an evolutionary point of view. One idea is that genes are involved in the evolution of language and human nature, but to date such ideas remain little more than hypothetical in nature.


Environmental factors associated with the development of schizophrenia include the living environment, drug use and prenatal stressors. Parenting style seems to have no major effect, although people with supportive parents do better than those with critical or hostile parents.Living in an urban environment during childhood or as an adult has consistently been found to increase the risk of schizophrenia by a factor of two,even after taking into account drug use, ethnic group, and size of social group. Other factors that play an important role include social isolation and immigration related to social adversity, racial discrimination, family dysfunction, unemployment, and poor housing conditions.

Substance misuse

A number of drugs have been associated with the development of schizophrenia, including cannabis, cocaine, and amphetamines. About half of those with schizophrenia use drugs and/or alcohol excessively.The role of cannabis could be causal, but other drugs may be used only as coping mechanisms to deal with depression, anxiety, boredom, and loneliness.

Cannabis is associated with a dose-dependent increase in the risk of developing a psychotic disorder with frequent use being correlated with twice the risk of psychosis and schizophrenia. While cannabis use is accepted as a contributory cause of schizophrenia by many, it remains controversial. Amphetamine, cocaine, and to a lesser extent alcohol, can result in psychosis that presents very similarly to schizophrenia.Although not generally believed to be a cause of the illness, people with schizophrenia use nicotine at much greater rates than the general population.

Developmental factors

Factors such as hypoxia and infection, or stress and malnutrition in the mother during fetal development, may result in a slight increase in the risk of schizophrenia later in life. People diagnosed with schizophrenia are more likely to have been born in winter or spring (at least in the northern hemisphere), which may be a result of increased rates of viral exposures in utero. This difference is about 5 to 8%.

This overall category includes the common varieties of schizophrenia, together with some less common  varieties and closely related disorders.

F20.0 – F20.3

General criteria for Paranoid, Hebephrenic, Catatonic and Undifferentiated type of Schizophrenia:
G1. Either at least one of the syndromes, symptoms and signs listed below under (1), or at least two of the  symptoms and signs listed under (2), should be present for most of the time during an episode of psychotic  illness lasting for at least one month (or at some time during most of the days).

(1) At least one of the following:
a)   Thought echo, thought insertion or withdrawal, or thought broadcasting.
b)   Delusions of control, influence or passivity, clearly referred to body or limb movements or specific thoughts,actions, or sensations; delusional perception.
c)   Hallucinatory voices giving a running commentary on the patient’s behaviour, or discussing him between  themselves, or other types of hallucinatory voices coming from some part of the body.
d)   Persistent delusions of other kinds that are culturally inappropriate and completely impossible (e.g. being  able to control the weather, or being in communication with aliens from another world).

(2) or at least two of the following:
e) Persistent hallucinations in any modality, when occurring every day for at least one month, when
accompanied by delusions (which may be fleeting or half-formed) without clear affective content, or when  accompanied by persistent over-valued ideas.
f)             Neologisms, breaks or interpolations in the train of thought, resulting in incoherence or irrelevant speech.
g) Catatonic behaviour, such as excitement, posturing or waxy flexibility, negativism, mutism and stupor.
h) “Negative” symptoms such as marked apathy, paucity of speech, and blunting or incongruity of emotional  responses (it must be clear that these are not due to depression or to neuroleptic medication).
G2. Most commonly used exclusion criteria: If the patient also meets criteria for manic episode (F30) or  depressive episode (F32), the criteria listed under G1.1 and G1.2 above must have been met before the disturbance of mood developed.
G3. The disorder is not attributable to organic brain disease (in the sense of F0), or to alcohol- or drug-related intoxication, dependence or withdrawal.
Comments: In evaluating the presence of the these abnormal subjective experiences and behaviour, special care  should be taken to avoid false-positive assessments, especially where culturally or sub-culturally influenced modes of expression and behaviour, or a subnormal level of intelligence, are involved ting

F20.0 Paranoid schizophrenia

A.   The general criteria for Schizophrenia (F20.0 – F20.3 above) must be met.
B.   Delusions or hallucinations must be prominent (such as delusions of persecution, reference, exalted birth, special mission, bodily change or jealousy; threatening or commanding voices, hallucinations of smell or  taste, sexual or other bodily sensations).
C.   Flattening or incongruity of affect, catatonic symptoms, or incoherent speech must not dominate the clinical  picture, although they may be present to a mild degree.

F20.1 Hebephrenic schizophrenia

A.   The general criteria for Schizophrenia (F20.0 – F20.3) above must be met.

B.   Either (1) or (2):
(1) Definite and sustained flattening or shallowness of affect;
(2) Definite and sustained incongruity or inappropriateness of affect.

C.   Either (1) or (2):
(1) Behaviour which is aimless and disjointed rather than goal-directed;
(2) Definite thought disorder, manifesting as speech which is disjointed, rambling or incoherent.
D.   Hallucinations or delusions must not dominate the clinical picture, although they may be present to a mild degree.

F20.2 Catatonic schizophrenia
A.   The general criteria for Schizophrenia (F20.0 – F20.3 above) must eventually be met, though this may  not be possible initially if the patient is uncommunicative.

B.   For a period of at least two weeks one or more of the following catatonic behaviours must be prominent:
(1) Stupor (marked decrease in reactivity to the environment and reduction of spontaneous movements  and activity) or mutism;
(2) Excitement (apparently purposeless motor activity, not influenced by external stimuli);
(3) Posturing (voluntary assumption and maintenance of inappropriate or bizarre postures);
(4) Negativism (an apparently motiveless resistance to all instructions or attempts to be moved, or
movement in the opposite direction);
(5) Rigidity (maintenance of a rigid posture against efforts to be moved);
(6) Waxy flexibility (maintenance of limbs and body in externally imposed positions);
(7) Command automatism (automatic compliance with instructions).

C. Other possible precipitants of catatonic behaviour, including brain disease and metabolic disturbances, have been excluded.

F20.3 Undifferentiated schizophrenia

A.   The general criteria for Schizophrenia (F20.0 – F20.3) above must be met.

B.   Either (1) or (2):
(1) There are insufficient symptoms to meet the criteria of any of the sub-types F20.0, .1, .4, or .5;
(2) There are so many symptoms that the criteria for more than one of the subtypes listed in B(1) above are met.

F20.4 Post-schizophrenic depression
A.   The general criteria for schizophrenia (F20.0 – F20.3 above) must have been met within the past twelve  months, but are not met at the present time.
B.   One of F20 G1.2 e, f, g or h must still be present.
C.   The depressive symptoms must be sufficiently prolonged, severe and extensive to meet criteria for at least a mild depressive episode (F32.0).

F20.5 Residual schizophrenia
A.   The general criteria for Schizophrenia (F20.0 – F20.3 above) must have been met at some time in the past, but are not met at the present time.
B.   At least four of the following ‘negative’ symptoms have been present throughout the previous twelve months:
(1) Psychomotor slowing or underactivity;
(2) Definite blunting of affect;
(3) Passivity and lack of initiative;
(4) Poverty of either the quantity or the content of speech;
(5) Poor non-verbal communication by facial expression, eye contact, voice modulation or posture;
(6)        Poor social performance or self-care.

F20.6 Simple schizophrenia

A.   Slowly progressive development over a period of at least one year, of all three of the following:
(1) A significant and consistent change in the overall quality of some aspects of personal behaviour, manifest as  loss of drive and interests, aimlessness, idleness, a self-absorbed attitude, and social withdrawal.
(2) Gradual appearance and deepening of “negative” symptoms such as marked apathy, paucity of speech, underactivity, blunting of affect, passivity and lack of initiative, and poor non-verbal communication (by facial  expression, eye contact, voice modulation and posture).
(3) Marked decline in social, scholastic, or occupational performance.
B.   Absence, at any time, of any symptoms referred to in G1 in F20.0 – F20.3, and of hallucinations or wellformed delusions of any kind, i.e. the subject must never have met the criteria for any other type of  schizophrenia, or any other psychotic disorder.
C.   Absence of evidence of dementia or any other organic mental disorder listed in section F0.

F22.0 Delusional disorder

A.   The presence of a delusion or a set of related delusions other than those listed as typical schizophrenic under F20 G1.1b or d (i.e. other than completely impossible or culturally inappropriate). The commonest examples  are persecutory, grandiose, hypochondriacal, jealous (zelotypic)) or erotic delusions.
B.   The delusion(s) in A must be present for at least three months.
C.   The general criteria for schizophrenia (F20.0 – F20.3) are not fulfilled.
D. Persistent hallucinations in any modality must not be present (but transitory or occasional auditory hallucinations that are not in the third person or giving a running commentary, may be present).
E.   Depressive symptoms (or even a depressive episode (F32.-)) may be present intermittently, provided that the  delusions persist at times when there is no disturbance of mood.
F.   Most commonly used exclusion criteria: There must be no evidence of primary or secondary brain disease as  listed under F0, or a psychotic disorder due to psychoactive substance use (F1x.5).

Specification for possible subtypes: The following types may be specified, if desired:

persecutory type; litiginous  type; self-referential type; grandiose type; hypochondriacal (somatic) type; jealous type; erotomanic type.


A.   The subject must develop a delusion or delusional system originally held by someone else with a disorder classified in F20-F23.
B.   The two people must have an unusually close relationship with one another, and be relatively isolated from other people.
C.   The subject must not have held the belief in question prior to contact with the other person, and must not have suffered from any other disorder classified in F20-F23 in the past


G1. An acute onset of delusions, hallucinations, incomprehensible or incoherent speech, or any combination of these. The time interval between the first appearance of any psychotic symptoms and the presentation of the fully developed disorder should not exceed two weeks.
G2. If transient states of perplexity, misidentification, or impairment of attention and concentration are present, they do not fulfil the criteria for organically caused clouding of consciousness as specified in F05 A.
G3. The disorder does not meet the symptomatic criteria for manic episode (F30), depressive episode (F32), or recurrent depressive disorder (F33).
G4. No evidence of recent psychoactive substance use sufficient to fulfil the criteria of intoxication (F1x.0), harmful use, (F1x.1), dependence (F1x.2) or withdrawal states (F1x.3 and F1x.4). The continued moderate  and largely unchanged use of alcohol or drugs in amounts or frequencies to which the subject is accustomed  does not necessarily rule out the use of F23; this must be decided by clinical judgement and the requirements  of the research project in question.
G5. Most commonly used exclusion criteria: absence of organic brain disease (F0) or serious metabolic  disturbances affecting the central nervous system (this does not include childbirth).

A fifth character should be used to specify whether the acute onset of the disorder is associated with acute  stress (occurring within two weeks prior to evidence of first psychotic symptoms).

F23.x0 without associated acute stress
F23.x1 with associated acute stress

For research purposes it is recommended to further specify the onset of the disorder from a non-psychotic to a clearly psychotic state as either:
abrupt (onset within 48 hours), or
acute (onset in more than 48 hours but less than two weeks


Note: This diagnosis depends upon an approximate “balance” between the number, severity and duration of the  schizophrenic and affective symptoms.
G1. The disorder meets the criteria of one of the affective disorders of moderate or severe degree, as specified for each sub-type.
G2. Symptoms from at least one of the symptom groups listed below, clearly present for most of the time during a  period of at least two weeks (these groups are almost the same as for schizophrenia

Emil Krapelein differentiated the psychiatric illness into two clinical types 1896

  • Dementia precox
  • Manic depressive disorder

Schizophrenia is split mind no split personality. Split is between thought and emotion

  • Eugen Bleuer coined the term schizophrenia in 1911
  • He described 4 primary symptoms
  • Ambivalence
  • Affective flattening
  • Loosening of association
  • Autism

Later on Kurt Schneider gave first rank symptoms
3 related to hallucinations
1st person hallucination or Audible thoughts – hearing ones thoughts spoken aloud.
2nd person hallucinations- commenting on subject’s activity
3rd person voices discussing the subject among themselves by the name of he or she.

3. Related to thoughts-
i)    Thought insertion: Pt does not have own thoughts, it has been inserted by external agency
ii)    Thought withdrawal: thoughts cease and patient thinks that thought had been removed by external agency
iii)   Thought broadcasting: Thoughts escape into outside world even the patient has not told theses thoughts to anyone.

3. Related to made phenomena
1. Made volition: Action and movements are under outside control
2. Made impulse: Drive or impulses seem to be alien and external;
3. Made affect (feelings): Feeling do not seem to be own and is in outside control

2. Other symptoms are:

  • Delusional perception: A private and illogical meaning attributed to a normal perception
  • Somatic passivity: One is passive recipient of bodily sensations imposed by external agency

According to DSM – IV, Duration of schizophrenia should be at least six months, out of which active symptoms should be present for one month.

Criteria: Two or more of the following symptoms should present.
a. Delusions
b. Hallucinations
c. Speech (disorganization)
d. Catatonic behavior
e. Negative symptoms
If duration of episode is > one month but < 6 months => diagnosis is schizophreniform disorder
If duration is > one day but < one month=> diagnosis is brief psychotic disorder. Other name is acute and transient psychosis’

Important point to be remembered: According to ICD – 10, the duration of schizophrenia must be at least one month as contrast to DSM –IV (six months)

  • Age of Onset: mid –10 to 25 for men; 25 to 35 of women
  • Late onset is said if schizophrenia has onset after age 45 Yrs
  • Lifetime incidence of schizophrenia is 0.5 to 5 per 10,000]
  • Lifetime prevalence of schizophrenia is 0.5% to 1%]


  • Paranoid / nonparanoid – Tsuang and Winokur
  • Positive / negative – h. Andreasen
  • Type I and Type II —- T.J. Crow

Paranoid Subtype

  • ** Most common type in world
  • Thought and perception disturbance
  • Good Prognosis: of positive symptoms
  • Late onset as compared to other types so that personality deterioration is not much. So good prognosis
  • Delusions are mainly persecutory, control and reference type and grandiose type
  • Hallucinations persecutory or grandiose content
  • Late onset and good prognosis schizophrenia

Hebephrenic (Disorganized Type)

  • Early onset and poor prognosis
  • Emotional and behavior disturbance; senseless giggling, mirror-gazing
  • Characterized by i) flattening / inappropriate affect; ii) disorganized speech in the form loosening incoherence, derailment

Catatonic Type

  • Motor disturbance
  • Best response to ECT
  • Also responds good to BZD, mainly Lorazepam
  • Characteristics of catatonic type are:

i) stupor ii) mutism iii) excitement iv ) Catalepsy v) negativism (motiveless resistance to all instructions or attempts to be moved) vi) rigidity vii) waxy flexibility viii) automatic obedience
ix) Speaks the things whatever examiner speaks  x) Echopraxia – imitates examiner’s action

xi) Ambivalence / ambitendency – also found in OCD xii) posturing examples are psychological pillow etc.

Undifferentiated Schizophrenia

  • Insufficient symptoms to meet the criteria for any of the above
  • So many symptoms that criteria are met for more than one subtype
  • Other various types are:
  • Residual schizophrenia
  • Simple schizophrenia: no delusion & hallucination, negative symptoms mainly, change of overall quality; very poor
  • prognosis

Positive and negative symptoms

Positive symptoms are those that most individuals do not normally experience but are present in people with schizophrenia. They can include delusions, disordered thoughts and speech, and tactile, auditory, visual,olfactory and gustatory hallucinations, typically regarded as manifestations of psychosis Hallucinations are also typically related to the content of the delusional theme. Positive symptoms generally respond well to medication.

Negative symptoms are deficits of normal emotional responses or of other thought processes, and respond less well to medication. They commonly include flat or blunted affect and emotion, poverty of speech alogia, inability to experience pleasure anhedonia, lack of desire to form relationships asociality, and lack of motivation avolition. Research suggests that negative symptoms contribute more to poor quality of life, functional disability, and the burden on others than do positive symptoms. People with prominent negative symptoms often have a history of poor adjustment before the onset of illness, and response to medication is often limited.

PROGNOSTIC FACTORS                     
GOOD                                      POOR
Late Onset                                Young Onset
Precipitating factor                    No precipitating factor
Acute onset (>2 days to 14 d)    Insidious onset (>2 weeks)
Married                                       Single, divorced or widowed
F/H of mood d/s                                   F/H of schizophrenia
Positive symptoms                   Negative symptoms
Good support

Prevalence of schizophrenia in specific populations
General population                                           1.0
Nontwin sibling of a schizophrenic patient        8.0
Child with one parent with schizophrenia         10.0
Dizygotic   twin of schizophrenic patient           12.0
Child with two parents with schizophrenia        40.0
Monozygotic twin of schizophrenic patient        47.0

Important Side effects of Typical Antipsychotics
Side Effects:
Neurological S/E (Acute extrapyramidal S/Es)
1. Akathisia – Greek word means inability to sit still or inner restless or urges to move.
Subjective and objective restlessness.30% patients on typical antipsychotics. May appear on 2nd or 3rd day but after 5th day. Propranolol is effective Rx.

2. Acute dystonia: slow, sustained painfull muscular contraction one group of muscle. 10% patients on typical antipsychotics Spasm of muscles of trunk, head and neck. Mostly occurs within 3 days; Risk
Factor— young male, high potency dopamine receptor antagonist. Rx Anti – parkinsonism drugs.
3. Parkinsonism – Symptoms like rigidity, bradykinesia, shuffling gait and tremor, 15% patients on typical antipsychotics. Rx Anti – parkinsonism drugs.
4. Neuroleptic Malignant Syndrome –Life threatening, up to 20 to 30% mortality.  Main features, i) Hyperthermia ii) Muscular rigidity iii) Autonomic instability including hyperthermia, tachycardia, increased blood pressure,’ tachypnea and dipahoresis, iv) Changing leves of sensorium;
often CPK and Aldolase; Creatinine phosphokinase (may be ) increased
Rx to NMS -1. Dantrolene – 1/v 0.8 to 2.5 mg/kg every 6hr with max 10mg /kg daily. If Symptoms subside, then orally 100 to 200mg daily
2. Bromoocryptine         3. Amantadine

Tardive Dyskinesia
Delayed painless peri-oral movements
Movement disorders that may occur following long – term treatment with anti – psychotic medication. Mainly mouth and tongue movements – lip smacking, sucking, puckering as ws as facial grimacing. ‘Also other choreoathetoid like movements.


  • Discovered by Cerletti and Bini 1938
  • Modified ECT means during anesthesia
  • Two types: Unilateral electrode over the nondominant
  • B/L Electrode
  • Most Common side effect of ECT is Amnesia. Mainly retrograde though some anterograde also
  • Usual dose for Adequate response is 100-150 volts for 0.1 to 1 sec with 200-1600mA current
  • Pregnancy and old age ECT  can be given

1.   Catatonic Schizophrenia
2.   Depression with suicidal tendency    
3.   Depression with psychosis
4.   Pts who are intolerant to S/E of medication non – responder
5.   Rapid recovery is desired in severe symptoms
6.   Patient’s preference

Non Psychiatric Indications for ECT:
1.   Parkinson’s Disease, particularly rigidity and bradykinesia
2.   Intractable seizure
3.   Neuroleptic malignant syndrome

C/I: No absolute contraindications
High risk patients are
1.   CNS lesions with increased intracranial pressure
2.   Neurosurgical procedures.
3.   Recent myocardial infarction or stroke within 4 to 6 weeks of events
4.   Uncompensated congestive heart failure

  • Brief seizure
  • Prolonged seizure > 180 secs

Number and spacing of ECT treatments

  • Bi-weekly or thrice weekly
  • 6 to12 depression
  • 1 to 4 delirium & catatonia
  • Mania and schizophrenia 8 to 20

Side effects:-

  • Headache
  • Delirium &confusion 10%
  • Memory loss 75%
  • Mortality 0.01 each patient