Psychopathology - V2 Models of Psychopathology

Scientist -Practitioner Approach

Psychologists use research findings to guide assessment, diagnosis and treatment of people with mental health disorders

What are models used to explain?

• Origins and maintainers of abnormal behaviour

• treatment

• prevention

What does research do?

test hypotheses derived from models

Aetiological Models

• Genetics

• Biochemistry

• Neuroanatomy

• Endocrine system

Genetics and Genetic Models

Genetics: Studies of gene-environment interactions

1. The pedigree method

2. Classical twin design

3. Adoption studies

4. Molecular genetics

What is the pedigree method?

Pedigree: is there a higher prevalence of disorders in the family of a proband than expected to occur by chance?

Proband

first person within a family presenting with the disorder

The Classical Twin Study

Compares concordance rates for Monozygotic (MZ) and Dizygotic (DZ) twins. If MZ > DZ rate: indicates genetic contributions • If MZ = DZ and both show high concordance; indicates shared environmental contributions

Adoption Studies (BAR)

• Compares the concordance of a disorder in adopted children:

• To their biological relatives

• To their adoptive relatives

What are the 2 ways Molecular Genetics can be studied?

1) candidate gene studies: one allele frequency test

2) GWAS, Genome wide association studies, assess whole genome

Allele

Alleles are alternative forms of a gene that determines a trait or disorder

Can one single gene cause a disorder?

No single gene has been found to be entirely responsible for mental disorders

Neurotransmitters

Chemicals that travel in the brain / nervous system (fast). These chemicals are released into the synapse between two neurons that carry signals from the terminal of one neuron to the receptors of another. All neurotransmitters are proteins

Neurotransmitter drug therapy

Most drug therapies increase or decrease the activity of specific neurotransmitters

Serotonin

•Regulates behaviour, mood & thought processes

What are some criticisms of Serotonin Studies?

-Not all studies have found support for a direct role of serotonin in depression

-Some find serotonin is part of a causal pathway, or conclude no support for the role of serotonin in depression

-Substantial minority of patients don’t respond to antidepressant medications that act on serotonin system

-Antidepressant medications can also be used to treat anxiety disorders as well as depression. So a bit unclear on the effects

What are some symptoms of low serotonin?

•Aggression

•Suicide

•Impulsive overeating

•Hyper-sexual behaviour

What drugs affect the serotonin system?

•Tricyclic antidepressants

•Serotonin specific reuptake inhibitors (e.g., Prozac)

Gamma Aminobutyric Acid (GABA)

•Inhibits a variety of behaviours & emotions

•Seems to reduce overall arousal

•Anxiolytic effects

Benzodiazepines (Valium)

•make it easier for GABA molecules to attach themselves to the receptors of specialised neurons

what is the role of Noradrenaline (Norepinephrine)?

used for flight-fight response, secreted by adrenal glands in the CNS, helps sympathetic nervous system

Dopamine

‘reward’ neurotransmitter, facilitates learning, can become addictive from other behaviours (e.g phone)

Parkinsons Disease

dopamine-producing cells damaged

Limbic System

connects forebrain, hindbrain and midbrain. Regulates emotions and learning

Damage to orbitofrontal Cortex

leads to disinhibited behaviour

Endocrine System

route for endocrine messages

bloodstream

Functions of Hormones

 Help regulate physiological processes

 Co-ordinate internal bodily processes with external events

Why is there comorbidity between PTSD and Depression

high cortisol can cause low serotonin

Hypothalamic- Pituitary - Adrenal HPA Axis

HPA axis is where the endocrine system and CNS interact and controls reactions to stress

5 stages of Psychosexual Development

• Oral: 0-1 ½ years

Anal: 1-3 years

•Phallic: 3-4 years

• Latency: 5-12 years

• Genital:11-20 years

What is the freudian view of psychosexual development?

if a developing child experiences some trauma at any one of those stages, they become fixated at a particular stage and then develop certain problematic characteristics

Psychodynamic Model

ID: • biological instincts • unconscious, pleasure

EGO: • reality principle • Uses defense mechanisms to ward off unpleasant feelings

SUPER EGO: Reasoning, ID and EGO combine

Freudians view of symptom formation

1) trauma in childhood

2) defence mechanisms

3) symptoms

Freudians view of symptom removal

1) free association

2) recovery of material

3) awareness and interpretation

Limitations of Psychodynamic Theory

1. Resistance to empirical investigation • How to study unconscious processes? 2. Emphasises abnormality rather than psychological health

3. Apparent ‘blaming’ attachment figures for individual’s concerns

4. Hasn't contributed to prevention or early intervention methods

5. Ascribes a medical model power structure to the patient and doctor / analyst