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 Think BING !
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 Neurotransmitters are the chemicals that carry information around the nervous system e.g. Dopamine, Serotonin, GABA Certain neurotransmitters have been thought to contribute to many psychological disorders
Neurotransmitter Imbalance Too much or too little of a particular neurotransmitter can lead to psychopathology 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.
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