People with schizophrenia--registering abnormal sensations through the sense organs (hallucinations) and harbouring odd beliefs, persecutory delusions for instance, and acting on those delusions--are definitely on the top of the list of mentally ill offenders.
Asst. Professor, Dept of Forensic
Medicine & Toxicology
• Psychiatry is the medical specialty devoted to the
study and treatment of mental disorders—which
include various affective, behavioural, cognitive and
• Forensic psychiatry: it deals with application of
psychiatry in the administration of justice.
• Due to the lack of proper mental illness
screenings & checkups for criminals, many
mentally-ill people are punished the same way
any other criminal would be and are deprived
of much needed health care and facilities
• Affective disorder : psychiatric disorder in which the
chief feature is a relatively prolonged affective change
of an abnormal degree. E.g. depression and mania.
• Is a spectrum of behaviors characterized by
certain abnormal mental or behavioral
• Condition of an individual who is suffering from
some defect or d/s of mind which affects his
personality, mental status, analytical faculties,
emotional process & his relation & interaction
with immediate/ total social environment.
• loss of memory
• May be seen in alcohol intoxication
& severe depression.
• Medico legal importance:
It can be used as an offence
(inadequate recall of what had
• It should be distinguished from
malingering in an attempt to avoid
the consequences of the offence.
• It is conduct that is performed by a person
whose consciousness is impaired to such an
extent that he is not fully aware of his actions.
• It is seen in epilepsy ,concussion or cerebral
disease, hypoglycemia & somnambulism.
• It is disturbance of consciousness where there is
impaired orientation, blunted critical faculties
and irrelevant or incoherent thought content.
• The patient suffer from insomnia ,hallucination
• It is seen in mental unsoundness, drug
intoxication, Dhatura poisoning and continuous
• It is fixed and false belief or erroneous judgment
which can’t be changed by logical argument or
evidence to the contrary.
• There are different types of delusions.
1. Persecutory (paranoid):- believes people
around are planning to do some harm and even
remark is looked upon suspiciously. E.g. In
2. Infidelity :- person believes his/her spouse to be
unfaithful though he/she is not so infact and
may even assault spouse/partner.
3. Reference :- the person believes that
people, things, events etc., refer to him in a
special way. He believes that even strangers
in the street are looking at him and talking
3. Nihilistic :- the person declares that he does
not exist and world has come to an end.
4. Grandeur :- the person believes himself to
be very rich but in fact he is not.
Medico legal importance
• Delusions are themselves not sign of insanity
and indicate only cerebral disorganization.
• They effect the thoughts and actions which
may lead to his committing criminal acts so
they can’t be regarded as fully responsible for
• It means degeneration of
mental faculties after full
• It may occur due to old
age, Alzheimer’s disease
involving brain, etc.
• loss of higher cognitive
functions & social
offences against children,
• The person does not believe in his own
existence or identity.
• It occurs in schizophrenia and depressive
• It is a delusion in which the person believes
that someone is deeply in love with him/her.
• It is intentional production or feigning of
physical or psychological symptoms which can
be attributed to a need to assume the sick
• It is fraudulent stimulation or exaggeration of
• It differs from factitious disorder in that the
production of symptoms is motivated by
external incentives whereas in factitious
disorder there are no external incentives but
psychological need for the sick role.
• A state of altered awareness during which an
individual forgets part or whole of his life,
leaves home and wanders.
• It is seen in hysteria, schizophrenia & epilepsy.
• It is a false sensory perception without any actual
• It can be visual, auditory, olfactory, gustatory, tactile
• A person suffering from hallucination maybe incited to
commit suicide or homicide.
• Visual hallucinations are commonest in organic mental
disorders such as delirium tremens, schizophrenia, etc.
• Auditory hallucinations are commonest in functional
disorders such as schizophrenia, delirium and psychotic
• These are false interpretation of sensory stimuli
often visual or auditory which has real existence.
• They maybe seen in normal persons, in dark or
during emotional stress and in organic brain disease
and maybe associated with hallucination.
• E.g. A dog maybe interpreted as a tiger.
A rope maybe mistaken for a snake.
• Sudden uncontrollable desire to
do something without any
motive or forethought.
• An insane person is incapable
of weighing the consequences
of the act and does it as soon as
the idea occurs to him.
• He has no power to control it.
• It is seen in dementia, acute
manias & epilepsy
Types of Impulses :
1. Kleptomania: irresistible desire to steal articles of
2. Pyromania: irresistible desire to set fire to things
3. Mutilomania: irresistible desire to mutilate animal.
4. Dipsomania: irresistible desire for alcoholic drinks at
5. Suicidal or homicidal impulses
6. Sexual impulses
• It is the interval occurring in the course of mental
disease when there is complete temporary
cessation of symptoms.
• The person is legally liable for his actions.
• In mania and melancholia lucid intervals are
• There is complete loss of speech.
• It is anxiety reaction characterized by
preoccupation with certain thoughts and ideas.
• The patient recognizes them as useless and tries to
get rid of them by persistent thoughts & acts but
the thoughts return to his mind in spite of all his
efforts to dispel them.
• Victim lives in constant fear of having done or
having omitted to do something.
• E.g. The patient spends whole night in frequently
seeing whether the door is bolted or not.
• Twilight states: It is state of diminished
awareness of acts of relatively short duration
of which he has no recollection.
• Oneirophrenia: It is a dream like state which
may last for days or weeks. The patient suffers
from mental confusion ,amnesia , illusions,
hallucinations, disorientation and anxiety.
• Types of mental illness arising out of mental
causes and not due to environmental or
• They are characterized by a withdrawal from
reality & living in a world of fantasy.
• mainly two types: (a) organic psychosis
(b) functional psychosis
B. Functional psychosis
(a) Schizophrenia- a personality split disorder
Thought disorder-atustic thinking, loosening of
association, thought blockade, neologism .
(c) Affect disorder.
(d) Disorder of behavior- withdrawal from reality,
self preoccupation, depersonalization, passivity
• Personality disturbances resulting from
reaction to life situation
i. anxiety neurosis
ii. hysterical neurosis
iii. phobic neurosis
iv. obsessive-compulsive neurosis
v. depressive neurosis
Persistent delusion disorder
• Presence of delusion of the different type for more
• Absence of significant hallucination
• Absence of organic mental disorder or
schizophrenia,or mood disorder.
Acute and transient psychotic disorder
• Acute onset within 48hr and gradual onset within 2
week, complete recovery with in 2-3 month
• It is a condition in which two people agree that at
the same time each will take his or her own life.
• It should have to be distinguished from cases where
murder is followed by suicide.
It means walking during sleep. It is state of
Somnolentia: It is midway between sleep and waking.
It is characterized by alternating stages of
depression ,excitement and stupor.
• Delirium tremens:
It is psychotic condition in alcoholics which
occurs due to sudden increase of dose and
sudden withdrawal. There are tremor, Insomnia,
mental confusion, loss of memory, disorientation
and hallucination of horror.
• Korsakoff’s psychosis:
It is a psychological and neurogenic deranged
condition occurring in some chronic alcoholics where
there is peripheral neuritis with polyneuritis,
muscular degeneration with weakness,
disorientation , some hallucination and retrograde
It is the state of a person under the influence of
alcohol such that he lost control to such an extent
that he is unable to perform his duty in which he was
engaged at the material time.
• an inherited d/s---causes degeneration of
nerve cells in the brain.
• broad impact on a person's functional abilities
• results in movement, thinking (cognitive) &
• can exhibit inappropriate sexual activities,
antisocial, cruel & violent behaviour
1. Management of property and affairs
If a mentally ill person is found incapable of managing
his property and affairs, but is not dangerous to
himself or to others, the court appoints a manager to
look after his property, granting his necessary power.
The manager is paid for his service from the property
or the income of the mentally ill person
2. Business Contract
• If one of the parties at the time of making a contract
was incapable of understanding what he was doing
due to insanity the contract is invalid.
• Contract entered into with a mentally ill person may
be valid, if the other party can show that he didn’t
know that the other party was mentally ill and that the
contract is a fair contract.
3. Marriage Contract
• A marriage is considered invalid, if at the time
of marriage either party
- is incapable of giving valid consent due to
- though capable of giving valid consent, has
been suffering from such a kind or degree of
mental disorder as to be unfit for marriage
- has been suffering from recurrent attacks of
4. Competency as a witness
- An insane person is not competent to give
evidence if he cannot understand the necessity of
telling the truth due to insanity.
- An insane person is competent to give evidence
if he is able to tell what he has seen and understands
the obligation of an oath
The consent is invalid if it is given by an insane
person who is unable to understand the nature and
consequences of the act.
6. Testamentary Capacity
is the mental ability of a person to make a valid will.
• A person affected by an insane delusion can make a
valid will if he delusion is not related in any way to
disposal of the property
Persons can make valid wills during lucid interval
• A will is considered valid even though the testator
committed suicide shortly after making a will if there
is no other evidence of mental disorder.
• A person of extreme age with defective memory can
make a valid will unless their mind has become so
impaired that they are unable to understand its
nature and consequence.
• A will executed by a dying person during delirium
would be invalid.
• A person may plead insanity to avoid :
→CONVICTION, if the accused was insane when the
alleged crime was committed
→ TRIAL, when the accused is insane and cannot plead
→ CAPITAL PUNISHMENT, when a condemned prisoner
The tests for determining
1. Mc. Naughten Rule ( the legal test) -
“an accused person is not legally responsible, if it is
clearly proved, that at the time of committing the
crime, he was suffering from such a defect of
reason from abnormality of mind, that he did not
know the nature and quality of the act he was
doing or that what he was doing was wrong.”
• This is the guideline followed in British courts for
consideration of the liability of a mentally ill person
who commits a crime
2. Durham Rule (1954)
“an accused person is not criminally responsible, if his
unlawful act is the product of mental disease or
3.Curren’s Rule (1961)
“an accused person is not criminally responsible, if at
the time of committing the act, he did not have the
capacity to regulate his conduct to the requirements
of the law, as a result of the mental disease or defect.”
4. The Irresistible Impulse Test (New
“an accused person is not criminally responsible, even if he
knows the nature and quality of his act and knows that he is
wrong, if he is incapable of restraining himself from
committing the act, because of free agency of his will has
been destroyed by mental disease.”
5. The American Law Institute Test (1972)
“a person is not responsible for criminal conduct if at the
time of such conduct, as a result of mental disease or defect
he lacks adequate capacity either to appreciate the
criminality of his conduct, or to adjust his conduct to the
requirement of the law.”
Insanity and Murder
• If the mental disorder impairs the cognitive faculties
of the accused, he is not held responsible for his acts.
• If insanity affects only emotions and the will, but not
the cognitive faculties, the person is held responsible
for his acts.
Doctrine of Diminished Responsibility
• If an unlawful act is committed by a person who is
suffering from some degree of mental illness, should
not be treated like a sane person who committed an
• According to this theory, such mentally ill persons
have diminished responsibility.
• Punishment for them for commission of and unlawful
act should be less.
• This theory could not gain much popularity as it is
not much impressive, because the criminal
responsibility of insane person should be considered
in such a way as, it either recognizes the
responsibility of the person committing the unlawful
act or does not recognize his responsibility anyway
Responsibility of Intoxicated Persons
In Civil cases
If any intoxicated person involves in any civil responsibility,
then the case will be considered according to the nature of the
work and merit of the consequences.
In Criminal cases
• An intoxicated person may not be held responsible for his act,
if at the time of commission, due to the effect of intoxication,
he did not understand the nature and quality of the act and its
consequences and legal position
• If the person has taken the intoxicating agent on his own and
with a mind to perform the criminal act easily, he will be held
responsible for its commission.
• Feigned Insanity: simulation of mental illness in
order to avoid or lessen the consequences of a
confrontation or conviction for an alleged crime.
• A consistent scheme should be used
• The patient should be seen first
• Patient should be put at ease and a warm empathic
relationship should be established
• Record patient’s responses verbatim
• Ask open-ended and non- directive questions
• Listen and show interest in patient
• Marital status
• Residential and office address
• Religion and socioeconomic background
In medico-legal cases, in addition, two identification marks
should also be recorded.
Informants should be assessed on the following
• Relationship with patient
• Intellectual and observational ability
• Familiarity with the patient and length of stay with
• Degree of concern regarding the patient.
Presenting chief complaints
Both patient’s and informant’s version should be
Patients own word should be used. Following points
should be noted-
• Onset of present illness.
• Duration of present illness.
• Precipitating factors
• Aggravating, maintaining and / or relieving factor
History of Present Illness
• When the patient was well last time
• Time of onset
• Symptoms of illness should be narrated
• The presenting complains should be expanded
• Any disturbance in physiological functions like sleep,
appetite and sexual functioning should be inquired
• Enquire about presence of suicidal ideation
• Important negative history( h/o head injury)
Past Psychiatric and medical history
• H/o similar illness, or in the past
• H/o psychotropic medication, alcohol and drug abuse
or dependence and psychiatric hospitalization.
• H/o serious medical, surgical or neurological illness.
Treatment history along with response to treatment
• Family structure
• Family history of similar or other psychiatric or
other serious medical illness
• Current social situation
• Perinatal history
• Childhood history
• Educational history
• Menstrual and Obstetric history
• Occupational history
• Sexual and marital history
• Interpersonal relationship
• Use of leisure time
• Predominant mood
• Attitude to self and others
• Attitude to work and responsibility
• Religious belief and moral attitudes
• Fantasy life
• Detailed General physical and Systemic
examination is must
• Physical disease etiologically important( for
causing psychiatric symptomatology),
accidentally co-existent, or secondarily caused by
psychiatric condition is often present
Mental Status examination (MSE)
I. Appearance and Behaviour
IV. Depersonalization and Derealization
V. Obsessional phenomena
VII. Illusions and hallucinations
IX. Attention and Concentration
Reference : Oxford Textbook of Psychiatry
Mental Status Examination
I. Appearance and behavior
General appearance –
1. Self neglect – alcoholism, drug addiction, depression,
2.Bright colored clothes – manic pts.
3. Wt. loss – physical illness, anorexia nervosa,
1. In depressed patients -
2. In anxious patients -
3. In patients with Parkinsonian side-effects -
elation, irritability and anger with unchanging
‘wooden’ expression of patients
Posture and Movement
• In depressed patient – sits leaning forward,
head inclined downwards and gaze directed to
• In anxious patient – sits upright with head
erect, often on the edge of the chair with
hands gripping its sides
• Maniac – often break social convention and are unduly
familiar to people they don’t know well
• Demented patients – respond inappropriately to
convention of medical interview or continue with their
private preoccupation as if interview were not taking
• Schizophrenic patients – behave oddly, some are
overactive and socially disinhibited, some are
withdrawn and others are aggressive
• Maniac – fast rate, amount of speech is
• Depressed/Demented – long pause, short
answer with little spontaneous speech
• Schizophrenic – lack of logical thread
• Thought blocking – sudden interruptions
• Flight of ideas- rapid shift of one subject to
• Mania – general warmth, euphoria, elation,
exaltation and/or ecstasy
• Anxiety – anxious and restless
• Depression – sad, irritable, angry and/or
• Schizophrenia – shallow, blunted, indifferent,
restricted, inappropriate and/or labile
IV. Depersonalization and derealization
V. Obsessional phenomena
VII. Illusions and hallucination
IX. Attention and concentration
• Digit forward and digit backward test
• 100 – 7 test
• 40 – 3 test
• Count backward form 20
• Enumerate names of months in reverse orders
• Immediate retention and recall
Digit span test
- digit forward test
- digit backward test
• Recent memory
• Remote memory
• Interviewer should have a provisional
estimate of how far the patient is aware of
morbid nature of his experiences
Mini - Mental State Examination
Attention and calculation 5
• Medical screening – Hb, TLC/ DLC, Blood glucose, Mean
Corpuscular Volume(MCV), Urinalysis, RFT, LFT, Thyroid
function test, ECG, HIV testing
• Toxicology screen for – alcohol, cocaine, opiates,
• EEG – seizures, dementia, pseudoseizures vs. seizures
• Brain imaging - CT scan – dementia, delerium,
- MRI scan – dementia
• Biochemical tests –
i. 5- Hydroxyindole acetic acid (5 - HIAA) –
decreased in depression, suicidal and/or
ii. Platelet MAO – decreased in depression
iii. Catecholamine levels – increased in organic
• Sexual disorders investigations –
papavarine test, serum
testosterone, penile doppler
i. Lactate provocation test – panic disorders
ii. Drug assisted interview (Amytal interview)-
Unexplained mutism, dissociative stupor