Psych 257 - Lecture 3

An Integrative Approach to Psychopathology

Multidimensional integrative approach

Mental illness as system of different reciprocal influences

◦ Complex interactions

◦ Cannot consider any one in isolation

• Treating one component of system will likely influence other components

1. Biological - genetics and neuroscience

2. Psychological - behaviour and cognitive

3. Social

Genetics and Psychopathology

• Genes contribute to almost all mental

disorders

◦ 1⁄2 the explanation

• Disorder mostly polygenetic

many genes influence illness - mental and physical 

Genes - Development of mental disorders 

a) Diathesis-stress model

b) Reciprocal gene-environment

c) Epigenetics

Diathesis-Stress Model

Environmental stress interacts with genetics to predict mental disorders

Genetic Vulnerability (Diathesis) X Stress (Predisposing) (Precipitating) → Psychological Disorder 

Predisposing: The underlying vulnerability that increases a person’s risk of developing a disorder. Usually biological, genetic, or psychological.

Precipitating: The external events or triggers that activate the underlying vulnerability. Typically situational or environmental stressors.

→ Everyone has a tipping point, some people have a lower/higher diathesis (cannot change this) - with enough stress, everyone would get the disorder 

Diathesis Stress: Research Support

→ Oldest/ simplest model

Serotonin levels (alleles)

ss- even with little stressor could develop

ll- (most proyectes) - even with high maltreatment, might not develop it

Gene-Environment Correlation Model + Research 

Environmental stress mediates the effect of genetics on psychopathology

• genetic endowment may increase the probability that an individual will experience stressful life events

Divorce Probability: Researchers found that adoptees resembled their biological, not adoptive, siblings in their history of divorce, suggesting that genetic factors contributed to divorce - being hard to get along with, not choosing good partners

Depression and support for stress- generation hypothesis: Unable to replicate any polymorphism or gene effects on depression, or gene-by-environment interactions on depression. They did find, however, that stressful life events increased the risk of depression

Epigenetic

• (Environment influence genes) Environment feeding into genome and passed down 

  • Historical record of all your ancestors environment (parents, grandparents, ..)

• Genes are turned on/off by cellular material outside of genome (“epi”) - methyl groups

  • Environmental factors influence epi-genome (instruction for DNA - tags on genome)

  • Passed down to next generation

Epigenetic - Research

• Baby turns into the adoptive mom behaviour

The researchers demonstrated that calm and supportive behaviour by the mothers could be passed down through generations of rats independent of genetic influences, because rats born to easily stressed mothers but reared by calm mothers grew up calmer and more supportive.

Early environment can modify the traits we pass along to our offspring, even if the genome does not change

• env that are supportive/positive early on is the best way to not develop these disorders

The brain and psychosocial functioning

All disorders → the main focus and target is usually biological

Brain structures and neurotransmitters influence psychosocial functioning

• Psychological treatments and factors can modify brain (CBT)

◦ NEUROPLASTICITY - biological and also experiences

→ Experience and therapy can change brain structure and function

Major neurotransmitters relevant to psychopathology

Norepinephrine (also known as noradrenaline), serotonin, dopamine, gamma aminobutyric acid (GABA - inhibitory), glutamate (the most common neurotransmitter - excitatory).

Initially: 

• reduced levels of GABA were initially thought to be associated with excessive anxiety,

• linked increases in dopamine activity to schizophrenia.

• found correlations between depression and high levels of norepinephrine and low levels of serotonin

• However, more recent research, described later in this chapter, indicates that these early interpretations were much too simplistic

The stress hormone cortisol. This system is called the hypothalamic-pituitary-adrenocortical axis, or HPA axis; it has been implicated in several psychological disorders. There is good evidence showing that a dysregulation of the HPA axis and other endocrine systems are linked to depression