Integrative Approach to Abnormal Behavior

Chapter 2

Nature v. Nurture?

Nature (biological influences) and nurture (psychosocial influences) are one-dimensional models. Issue is one of Causality? What leads to abnormal behavior???? Our tendency is to simplify.

Result in incomplete understandings of psychological disorders

Multidimensional models allow for a more complete understanding of psychopathology. They are systemic!

Integrated model attempts to understand of the complex interaction of multiple influences

Abnormal behavior is multiply determined by multiple pathways

behavioral

genetic brain

developmental

social

emotional

cognitive

psychological disorder

The Interaction of Genetic and Environmental Effects

Models of Interaction The Diathesis-Stress Model

Genetic vulnerabilities that are only expressed in the presence of certain environmental stressors

The smaller the vulnerability, the greater the life stress needed to result in the disorder, and conversely.

Reciprocal Gene-Environment Model Newer model, proposes that genetic influences behavior to

increase likelihood of encountering activating stimuli. Genetic endowment increases the likelihood of encountering stressful life events.

Non-Genomic Inheritance of Behavior Genes are not the whole story. Early learning (parenting

styles and nurturance) may over-ride genetic predisposition.

Neuroscience Contributions to Psychopathology

The Field of Neuroscience The role of the nervous system in disease and

behavior

The Central Nervous System (CNS) Brain and spinal cord They process all information received from sense

organs

The Peripheral Nervous System (PNS) Somatic and autonomic branches

Neuroscience and the Central Nervous System

The Neuron Soma – Cell body Dendrites – Branches that receive messages from

other neurons Axon – Trunk of neuron that sends messages to other

neurons Axon terminals – Buds at end of axon from which

chemical messages are sent Synapses – Small gaps that separate neurons

Neurons Function Electrically, but Communicate Chemically Neurotransmitters are the chemical messengers, and

have been critically involved in psychological disorders.

Neuroscience: Functions of MainTypes of Neurotransmitters

Functions of Neurotransmitters To understand functions, we have studied effects of agonists,

antagonists, and inverse agonists Most drugs are either agonistic or antagonistic Agonists increase the activity of a neurotransmitter by mimicking

its’ effects; antagonists decrease or block a neurotransmitter; inverse agonists produce effects oposite to those produced by the neurotransmitter.

Main Types and Functions of Neurotransmitters Serotonin (5HT)- 5 hyroxytryptomine. Regulates behavior, mood

and thought processes. Associated with depression, impulsivity, and over-reactivity.

Gamma aminobutyric acid (GABA) and benzodiazepines. Best known for their effects on anxiety reduction.

Norepinephrine and beta blockers. Regulation of physiological responses, such as heart rate and respiration.

Dopamine and L-Dopa-activate other neurotransmitters, and an excess have been implicated in schizophrenia.

Implications of Neuroscience for Psychopathology

Relations Between Brain and Abnormal Behavior Examples include obsessive compulsive disorder and

schizophrenia

Experience Can Change Brain Structure and Function

Therapy Can Change Brain Structure and Function Medications and psychotherapy