1. Biological Approach to Abnormality

2. Causes of Abnormality
The biological model of abnormality assumes mental disorders as illnesses with a physical cause.
The medical explanations of abnormality are:
Neuroanatomy (structure of brain)
Brain biochemistry (function of brain)
These may be the result of:
Genetic factors
Brain damage (infection or lesions)

3. Neuroanatomy This involves the structure of the brain.
People with schizophrenia have smaller brains but the lateral ventricles are 40% larger

4. Brain Biochemistry
Abnormality may lie in a person’s biochemistry, e.g.
Schizophrenia is associated with high levels of the neurotransmitter Dopamine (important roles in behaviour and cognition,  incl. mood, attention, working memory)
Depression is associated with low levels of serotonin (the “happiness hormone”)
However, these are correlations, so can not tell whether this is a cause or an effect of the disorder

5. Genetics Patients may inherit genes which cause mental disorders..
Although it can be hard to decide whether they developed the illness through genetics or being in a similar environment to that person.
Kendler et al (1984) - relatives of someone who had schizophrenia were 18 times more likely to develop it.
Concordance rates in twins: do monozygotic (MZ or identical) have higher concordance rates than dizygotic (DZ or unidentical) twins?

6. Results Of Twin Studies
Dizygotic Twins
Monozygotic Twins
Schizophrenia
Gottesman (1991)
Depression
(Moore & Jefferson, 2004)
17%
48%
20%
46%
Need to differentiate between ‘genetics’ and ‘biology’
Watson et al (1998) – Monkeys in social isolation show low serotonin levels ain depression symptoms
So ‘life’ matters!

7. Evaluation of the Biological Model
Well established: evidence from science such as biochemistry and scans.
Drug therapies: based on the biological model and have often proved effective in reducing symptoms
BUT
Disorders appear to have a biological vulnerability factor which triggers the disorder when stress is encountered
a.k.a. ‘Diathesis Stress’ theory
Biological factors seem to play a greater role in some disorders e.g. Schizophrenia than others, e.g. phobias
Model ignores social and psychological factors

8. Biological Treatments
Psychosurgery
Electroconvulsive Therapy (ECT)
Drug Therapy

9. Psychosurgery
Surgically lesioning part of the brain to control symptoms of patient (in 1930s & 40s); e.g.
Lesion to amygdala to control aggression/violence
Frontal lobotomy to ‘cure’ schizophrenia
No evidence is cured anything, just made patient more manageable
Now VERY rarely used, for very severe epilepsy (by severing corpus callosum)

10. Electroconvulsive Therapy
In 1930’s, explanatorily used for schizophrenia but seemed to help depression
Reason for its success is unknown, but presumably ‘resetting’ neurotransmitter activity helps break some cognitive/‘thought’ cycles
Still used in treating depression (though only for very severe and treatment resistant cases)
Can lead to some memory issues

11. Drug Therapy ~Schizophrenia~
In 1950’s, chlorpromazine -a.k.a. Thorazine- (a sedative!) was found to reduce hallucination & delusions
We now know it reduces dopamine activity
Newer drugs -such as clozapine- also target additional neurotransmitters (incl. serotonin); more effective with less side effects
BUT only works on 50-60% of patients
Suppresses not cures; 80% relapse of those who go off

12. Drug Therapy ~Depression~
First wave of drugs in 1960s, both raised serotonin levels:
Monoamine-oxidase inhibitors (MAOIs)
Interact badly with certain foods & medicines
Tricyclic anti-depressants (TCAs)
Long term usage related to heart problems
1990’s brought Selective Serotonin Reuptake Inhibitors (SSRIs, eg. Prozac); safer and more effective
60-70% success rate, but placebo has ~30% success rate!
Target bio-processes, but not deal with cognitive biases
Dependence & side effects (incl. aggression & suicide)

13. Biological Model Evaluation (AO2)
Scientifically testable and supported, BUT not conclusive (however there is a clear system for improvement)
Efficacy depends on degree of biological causation
Model overlooks environmental/cognitive factors
Side effects & issues of dependence
Ethical issues of informed consent & stigmatisation

14. For your general information (you don’t ‘need’ to know this!)…
A psychiatrist:
A psychologist:
Is trained as a medical doctor, then specialises in psychiatry
Has a degree in psychology, then has three years of training to become a clinical psychologist
Is likely to diagnose abnormalities using the medical approach - i.e. assume there is an underlying physical cause to the mental abnormality
Is likely to diagnose abnormalities using one of the psychological approaches e.g. using the psychodynamic approach they will assume that unresolved childhood conflicts are the basis of the mental abnormality
Is likely to prescribe a medical treatment, such as drugs or surgery
Is likely to prescribe a therapeutic treatment, such as cognitive behavioural therapy or psychoanalysis

15. Biopsychosocial Models
Integration of:
Biological
Social
Psychological (Esp. cognitive & behavioral)
Abnormality caused by:
Interaction of these factors, no one cause
Relative importance of each factor depends on individual and environment

16. Biopsychosocial Models (AO2)
Pros:
Take into account interactions between forces affecting psychological functioning
Combines treatment methods – tailored for individual
Cons:
Hard to find one specific cause of problems
Can be difficult to research, hard to find single IV’s.