Comparing Models of Abnormal Behavior

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Let's look more closely at four models of abnormality, which you can then make your comparisons for your final copy.

Those in the field of abnormal psychology study people's emotional, cognitive, and/or behavioral problems. Abnormal behavior may be defined as behavior that is disturbing (socially unacceptable), distressing, maladaptive (or self-defeating), and often the result of distorted thoughts (cognitions).

1. The biological model

The biological model takes a medical perspective. It main focus is that psychological abnormality is an illness brought about by malfunctioning parts of the organism. It is typically focused on the BRAIN. Biological Theorists explain abnormal behavior in terms of brain anatomy and chemistry. Brain anatomy is the brain is composed of 100 billion nerve cells (called neurons) and thousands of billions of support cells (called glia) and wthin the brain, large groups of neurons form distinct areas called brain region. It plays a part in abnormal behavior. For example, clinical researchers have found connections between certain psychological disorders and problems in specific brain areas. Example: Huntington's disease & basal ganglia (forebrain).

Brain chemistry

Information spreads throughout the brain in the form of electrical impulses that travel from one neuron to one or more others. An impulse is first received at a neuron's dendrites, travels down the axon, and is transmitted to other neurons through the nerve endings. Neurons don't touch; they are separated by a space (the synapse), across which a message moves. When an electrical impulse reaches a nerve ending, the nerve ending is stimulated to release a chemical (a neurotransmitter or "NT"). Some NTs tell receiving neurons to "fire"; other NTs tell receiving neurons to stop firing

Role of brain chemistry in abnormal behavior

- Researchers have identified dozens of NTs
- Examples: serotonin, dopamine, and GABA
- Studies indicate that abnormal activity in certain NTs can lead to specific mental disorders
- Examples: depression (serotonin and norepinephrine) and anxiety (GABA)
- Additionally, researchers have learned that mental disorders are sometimes related to abnormal chemical -activity in the endocrine system
- Hormone release, triggered by a variety of factors, propels body organs into action. Abnormal secretions have been linked to psychological disorders
- Example: cortisol release is related to anxiety and mood disorders
(http://www.southalabama.edu/psychology/docs/spring2007/340/CWCh03.pdf).

1. Biological abnormalities - genetics
- Humans have 23 pairs of chromosomes, each with numerous genes that control the characteristics and -traits a person inherits
- Studies suggest that inheritance plays a part in mood disorders, schizophrenia, mental retardation, Alzheimer's disease, and other mental disorders
- Aren't able (yet) to identify specific genes
- Don't know the extent to which genetic factors contribute to disorders
- Seems no SINGLE gene is responsible for a particular behavior or disorder

2. Biological abnormalities - evolution
- Genes that contribute to mental disorders are viewed as unfortunate occurrences:
- May be mutations
- May be inherited after a mutation in the family line
- Evolutionary theorists argue that we can best understand abnormality by examining the millions of years of human evolution
- Looking at a combination of adaptive behaviors of the past, genes, and the interaction between genes and current environmental events
- This model has been criticized and remains controversial.

3. Biological abnormalities - viral infections
- Infection provides another possible source of abnormal brain structure or biochemical dysfunction
- Example: schizophrenia and prenatal viral exposure
- Interest in viral explanations of psychological disorders has been growing in the past decade
- Example: anxiety and mood disorders

Biological ...