• Understand psych disorders as brain diseases
• Understand the roles of bio-psychosocial factors
• Understand the study approaches for identifying etiological factors
• Understand the stress-diathesis model
• Learn about clinical formation

Subjective vs. Objective

• Organic: gross pathology inside brain, seen with imaging studies, CN examinations
• Functional: no gross pathology inside brain, minor findings (eg. Enlargement of ventricles) - impair brain in cognitive processes, abstract, subtle

• Body (including body systems + organs) affect brain function
• Brain generates ideas/ integrates sensory input -> behaviour + emotion
• Brain is basis for some behaviour, but not all
• Brain is not origin of mind
• Psych: interpret symptoms as arising from brain (eg. NT)

• Environment: psychological, stress, interpersonal
• Significant role in aetiology of psych disorders

• Continuous psychotherapy - can change NT system/ neural pathway as learning process

Phenomenological & syndromal approach

• Try to capture symptoms (rely on Pt) that cluster together and form a syndrome (whether fits into a particular disease pattern)

• Eg. Schizophrenia Pt can also have depressive symptoms
• Eg. Manic-depressive disorder may include psychotic symptoms
• Esp. overlapping in neurotic disorders - eg. Panic with agoraphobic, anxiety and depression

• Standardised, mutually agreed upon
• Operational criteria to label a particular disease (based on phenomenological approach without no confirmation from biological/ laboratory)

• Demonstrate problem clusters in family (family studies) - prevalence rate within family members is higher if a particular person has a disease cf. with general population
• Twin studies: can not exclude environmental effects
• Adoption studies

• Study aggregation of affected members in a family as compared to the general public
• Cannot distinguish genetic or shared environment (diet, living environment, parenting, social class specific infection within the same family)
• Familial vs. inheritance

Risk of schizophrenia with family Hx as follows

• 1 parent 13%
• 2 parents 46%
• 1 sibling 10%
• 1 child 6%
• 1 grandparent 5%
• Nephew / niece/ uncle/ aunt 3%
• Cousin 2%
• General public 1%

Every country, culture

Bipolar proband

• Bipolar 8%
• Unipolar 11%

Unipolar proband

• Bipolar 0.6%
• Unipolar 9%

General population

• 1% bipolar
• 3% unipolar (severe hospital patients)

MZ Twin

• Split from 1 fertilised egg
• Identical - 100% genetic sharing

DZ twin

• From 2 fertilised eggs
• Just like sibling - share 50% genes

MZ > DZ concordance - due to genetic

MZ concordance not equal 100% - environmental factor is also important

Still cannot distinguish genetic from shared environment

• MZ concordance 45%
• DZ concordance 15%
• Equal risk for offspring of both affected and unaffected MZ discordant twins!
• Unexpressed genes?

Bipolar

• MZ concordance 72%
• DZ concordance 14%

Unipolar

• MZ concordance 40%
• DZ concordance 11%

Indicates interaction bet genetics and environment

• Family, twin and adoption studies consistently show that major mental illness (eg. Schizophrenia and affective disorder) are inherited in nature
• Next stage will be ID abnormal genes
• Intermediate phenotype important but difficult to find

1. NEUROCHEMISTRY

• Dopamine
• Serotonin
• NA
• GABA
• Glutamate
• ACh, etc

• Raphe nucleus - fibres to limbic system/ cortex/ spinal cord
• Important for emotional control/ mood/ appetite/ expression/ anger
• Problems in depressant/ anxiety disorders
• Drugs act on this system

• Release serotonin from nerve terminal, bind to receptors, trigger post-synaptic events
• SSRI (eg. Prozac): bind to serotonin transporter (serotonin in XS in cleft due to decreased uptake into nerve terminal)
• Amine hypothesis of depression; too little serotonin in synaptic cleft

1. NEUROPATHOLOGY

• Structural neuroimaging - MRI
• Histopathology
• To show abnormal cell organisation/ neuronal death

SLIDE: Schizophrenia in MZ Twins

• Discordant
• 3rd ventricle larger in affected twin (robust finding for chronic schizophrenic illness)
• Clinically, may not be able to detect this enlargement of ventricle (only statistical finding) - can only tell when compare to unaffected twin

1. NEUROPHYSIOLOGY

• Cognitive event related potentials - when they hear tone, press button (cognitive engagement) - measure EEG response as measure of brain activity
• Functional neuroimaging - fMRI, SPECT, PET

DIAG: Schizophrenic illness (PET scan)

• Frontal lobe has less metabolism in Schizophrenic Pt's
• Use twins: should share same genetic material, brain structure more or less the same (better than disease vs. control)

1. EARLY LIFE EXPERIENCE

• Loss of parent
• Sexual or physical abuse
• Any other events which may be crucial to the formation of personality
• Formed attitudes towards other people/ the world in general (stress - suppress formation, uneven formation) - eg. Paranoid, impulsive

1. PSYCHODYNAMIC FACTORS

• Instinctual forces that are not accessible to awareness (eg. For food, want power but not aware of this)

• Part of the mind which is accessible to awareness (eg. Want power but know it's not the right time)

• Executive function of the mind which provides a sense of self
• To withstand external challenges the ego uses defence mechanism
• Tries to satisfy both urges and super-ego
• Super-ego: don't do that - unethical/ violate religious beliefs/ law

• Denial: process of rejecting unacceptable thoughts, feelings or impulses
• Regression - returns to earlier stage of developmental functioning
• Rationalisation - superficially logical but invalid thinking to avoid stressful reality
• Displacement - redirection of feelings to another object to reduce the threat of real feelings
• Projection - blaming others for one's own fault
• Sublimation - transformation of socially unacceptable feelings or thoughts to socially acceptable ones
• Reaction formation - transforming unacceptable thoughts or feelings to its opposite

1. COGNITIVE BEHAVIOURAL FACTORS

Based on learning theory

Through classical, operant or modelling an individual acquires responses to the internal and external environment

• Classical: association, conditional response
• Operant: +ve or -ve reinforcement (reward/ punishment), behaviour depends on whether consequence was good or bad
• Modelling: modelling others; model parents when young, if parents defective (mental illness, substance abuse) children will model this behaviour
• Psychiatric disorders or psychopathology may arise due to a limited and maladaptive way of viewing the self or the environment (eg. If gloomy person, and small problem occurs, think problem is hopeless and contemplate suicide, etc.)

• Unemployment
• Poverty
• Job-related stress
• Family structure

• Friends
• Relatives
• Colleagues
• Organisation/ institutions (church, school)

• Variable
• May not appear important to you, but may be very important to that person

Stress (environment, biological)

• Eg. Biological - infection
• Eg. Psychological - finance

Diathesis (vulnerability, risk to develop a particular disease)

• Eg. Biological - genetic
• Eg. Psychological - personality

Additive model: have propensity plus stress -> mental breakdown