Psychological Approaches to Psychopathology

Variety of approaches which make assumptions about the

cause of abnormality

Biological – biological factors Cognitive – thought processes underlying the process Behavioural – learning experiences are critical in

understanding abnormality Psychodynamic – early experience and unconscious

processes are the key influences on behaviour (normal and abnormal)

abnormality

the biological approach

Lesson objective

To understand how the biological approach views

mental disorders

NB Biological Approach is also known as the Medical Model and/or Somatic* Model

* somatic = ‘of the body’

Psychological disorders are physical illnesses...

When the same symptoms frequently occur together, they represent a syndrome or disorder. The cause, or ‘aetiology’ may be one or more of the following:

Brain injury Infection Neurotransmitters Genetics

ThinkBING !

Brain injury

Remember Phineas Gage?

Accidental Brain damage can lead to psychological disorders.

After the accident, Phineas Gage was described as impulsive, disordered and having a different personality

http://www.youtube.com/watch?v=yXiM-nDYzX0

Brain damage

A degeneration or malformation of brain cells can cause memory loss often present in Alzheimer’s disease.

Korsakoff’s syndrome occurs when drink and drugs damage part of the brain involved in memory.

Infection

Sometimes an infection that causes one illness can lead to a secondary illness that has psychological symptoms.

Infection

Syphilis bacterium causes a sexually transmitted disease known as syphilis. It causes short-lived sores followed by general paresis

- forgetfulness, mental deterioration and delusions of grandeur and persecution.

The influenza virus has been linked to schizophrenia.

Brown et al (2004) found that 14% of schizophrenic cases may be linked to

the foetus being exposed to the ‘flu virus in the womb during the first trimester.

Neurotransmitter Imbalance

Certain neurotransmitters have been thought to contribute to many psychological disorders

Neurotransmitters are the chemicals that carry information around the nervous systeme.g. Dopamine, Serotonin, GABA

Neurotransmitter Imbalance

One of the factors involved in schizophrenia is an excessive amount of dopamine

High levels of serotonin have been thought be involved in the manic state of bi-polar depression.

Too much or too little of a particular neurotransmitter can lead to

psychopathology

Genetics

Individuals may inherit a predisposition* to certain illnesses. These are carried on genes, through DNA, which pass from one generation to the next

*PREDISPOSITION = Increased vulnerability to a particular disease based on genetic factors

Genetics

Every human has 46 chromosomes (DNA) divided into 23 pairs.

During reproduction, 23 chromosomes from mum and 23 chromosomes from dad are combined to make an embryo (cells before a baby)

Genetics

This is how we get our characteristics from both of our parents.

If a disorder is caused genetically then we would expect individuals who are closely related to be more likely to have it

Genetics

How do we measure this?

Concordance rate: measures how often two individuals who are closely related have the same disorder.

Genetics Research

Twin Studies:

Twins can be identical (monozygotic,MZ) or fraternal (dizygotic, DZ).

Monozygotic (MZ) twins have identical DNA

McGuffin et al (1996)

Studied twins where one of the pair already suffered from depression.

Assessed the co-twin and found…

46% concordance rate for depression (MZ)

20% concordance rate for depression (DZ)

Gottesman (1991)

Meta-analysis of about 40 twin studies

Found concordance rate for schizophrenia of 48% in monozygotic twins and 17% in dizygotic twins

Kendler, Masterson and Davis (1985)

Relatives of schizophrenics were 18 times more likely to be diagnosed with schizophrenia than we would normally expect.

Strengths of biological approach

Techniques have shown that there are biological components. Brain scanning has improved our ability to see this.

Research shows that there can be a genetic link

Drugs can work as treatment options When it explains things, it is scientific No blame

Weaknesses of biological approach

Reductionist Genetics don’t provide a complete

explanation, e.g. diathesis-stress Drugs won’t work for everyone Focus of curing symptoms, not cause Might encourage patients to be passive