Abnormal Psychology: Etiology of Major Depressive Disorder

Automatic Thoughts

Semi-conscious sub-vocal narrative that naturally occurs in people's minds as we do our daily activities

cognitive styles

The way people typically interpret or understand events in their lives

biased attention

we notice examples that fit the pattern more readily

- Individuals with depression spend more time focusing on the negative and it confirms negative thought processes

What are three types of locus of control?

internal

external- others

external- chance

Conclusion of Aiken and Baucom, 1982

Positive correlation between external locus of control and depression

Who developed the Cognitive Theory of Depression?

Beck

Whose theory forms the basis for Cognitive Behavioral Therapy?

Beck (Cognitive Theory of Depression)

According to Beck, what are the three elements of depression?

Negative beliefs about self, the world and the future

In Beck's theory, what are the three elements of depression called?

Cognitive triad

-Negative beliefs about self, the world and the future

Negative self-schemata

Negative beliefs become generalized

See fault in everything and they cannot control it (external locus of control)

faulty thinking patterns

Logical fallacies

Irrational conclusions

Cognitive Styles linked to MDD

Negative cognitive styles increase vulnerability to depression when faced with stressful events

Aim of Alloy, Abramson and Francis, 1999

to investigate whether particular cognitive styles (positive or negative) is associated with the development of depressive symptom

Conclusion of Alloy, Abramson and Francis, 1999

Negative cognitive styles may influence the development of major depression

How does Bates, 1999 support the findings of Alloy, Abramson and Francis, 1999?

He found that depressed participants who were given negative automatic thoughts statements become more and more depressed. This shows the connection between negative thoughts and MDD

Conclusion of Caseras et al., 2007

Negative attention bias potentially is one of the mechanisms of major depression

Which cognitive theory was explored by Caseras et al., 2007?

biased attention

Which cognitive theory was studied by Alloy, Abramson and Francis, 1999?

Cognitive Styles

Strengths of Cognitive Explanations of Depression

-Strong empirical support

-May emphasize the ability of the individual to overcome it

CBT is considered and effective treatment of MDD

Limitations of Cognitive explanations of depression

-Correlational nature of research

-Difficult to distinguish between thinking that causes depression and thinking that is the result of depression

-Negative thinking style determined by their predisposition to depression

-Reductionist

-May blame the person with MDD

Vulnerability Factors Proposed by Brown and Harris

-3+ children

-Lack of intimate relationship

-Loss of mother

-Lack of employment

-In Elderly.... (Early loss of a parent, Lack of religious participation)

Are social factors of MDD focused on vulnerability OR etiology?

vulnerability

How do social networks influence MDD?

The structure of your social network impacts the rate of depression

-Symptoms spread person to person

-Up to 3 degrees of separation

Conclusion of Kivela et al., 1996

social factors and social ties may predict the onset of depression with age

Which social factor of MDD did Rosenquist, Fowler and Christakis, 2011

study?

social networks impact on the rate of depression

conclusion of Rosenquist, Fowler and Christakis, 2011

Symptom of depression may spread along network or social connections (like a virus)

Who were the participants in Kivela et al., 1996 research on MDD?

Elderly in Finland

How does culture effect MDD?

-Culture does not cause depression (not an etiology)

-Role → moderating the development and expression of MDD

conclusion of Hammen and Krantz, 1976

Individuals suffering from depression made significantly more logical errors in their interpretation of stories about stressful situations. *page 297

Which cognitive theory did Hammen and Krantz, 1976 study?

logical errors: negative cognitive styles

How do cultural perceptions impact MDD?

development and presentation of MDD symptoms

what is another word for cultural perceptions, in regard to MDD?

cultural stigma

conclusion of Patten, 1991

lack of intimate relationships increases the risk of developing depression 3.7 times

provoking agent

negative life events such as being made redundant

self-blame schema

individuals feel personally responsible for every bad thing that happens

Kirmayer's Explanatory Models theory

Culture determines the socially acceptable symptoms for disorders

Bidirectional ambiguity

An uncertainty in whether or not x causes y, or if they are simply correlated.

Who studied individuals in Rwanda to determine the post-genocide depression prevalence?

Bolton et al (2002)

How did Bolton et al., 2002 develop their research materials?

used local experts to design a behavioural checklist that could be used for diagnosis.

What do vulnerability models of depression focus on?

- genetic influence

- Environmental stressors.

- The way that individuals cope with environmental stressors.

Results of Joiner's study

- negative thinking patterns

- negative environmental stimulus

Results of Brown and Harris (1978)

33/37 women with depression had experienced a negative life event in the year that they became depressed

etiology

a set of causes of a disease or condition

(separated into biological, cognitive and sociocultural)

The Falconer Model

assumes that phenotype is comprised of three types of influences: Genetics, Shared environment, Individual Environment

Implications of Sullivan, Neale and Kendler (2000)

established the estimate of heritability of major depression at A = 37%, with a minimal contribution of shared environment (C=0%) and a substantial contribution of unique/individual environmental factors (E =63%)

Aim of Kendler et al (2006)

Aim: To compare genetic effects on MDD first in males and females and second across different generations.

Conclusion of Kendler et al (2006)

Conclusion: Heritability of MDD was significantly higher in women than men

No evidence was found for differences in the roles of genetic and environmental factors across genterm-16erations

phenotype

Observed characteristics such as the presence of symptoms of MDD. Comprised of three types of influence: genetics, shared environment, and individual environment. Can be written in the following form: 1= A+C+E

Gene-environment interaction

occurs when two different genotypes respond to the same environment in different ways

Aim of Silberg et al (1999)

investigated the link between susceptibility to depression and environmental factors (stressful life events)

Conclusion of Silberg et al (1999)

The effect of negative life events on depressive symptoms in adolescent girls was stronger, suggesting that genetic predisposition causes girls at this age to be more vulnerable to negative or stressful events.

Implications of Silberg et al (1999)

Results exemplifies one of the ways in which genes may interact with the environment: environmental factors serve as necessary mediators or triggers for genetic predisposition

Molecular genetics

allows us to identify specific genes influencing complex psychological disorders

Method of Caspi et al (2003)

Longitudinal study on possible role of gene 5-HTT in depression.

Conclusion of Caspi et al (2003)

found that a functional polymorphism in a serotonin transporter gene (5-HTT) moderated the influence of stressful life events on depression.

What was the theory of Chiao and Blizinsky (2010)?

"culture-gene coevolution theory"

"culture -gene coevolution theory"

posits that cultural values buffer genetically susceptible populations from increased prevalence of affective and mood disorders

Gene environment correlation

Genes and environment are important in determining he development of a mental disorder.

Breakdown of phenotype

A=genetics

C=shared environment

E= and individual environment

Gene-Environment Correlation (rGE)

Gene predisposition can influence the environment.

Gene-Environment Interaction IGxE)

Different genotypes will react differently to the same environment. For example: predisposition will make people more vulnerable to stressful events.

Passive gene-environment correlation (passive rGE)

Parents provide a rearing environment. Genes and environment are correlated. Ex. Parents might pass a genetic predisposition to depression and provide a high-demanding stressful environment.

Strengths of Genetic argument for MDD

Twin studies are highly reliable, large samples now have revealed a lot of genetic variation. Modern research sees interaction between environment and biology.

Limitations of Genetic Argument for MDD

Correlational studies do not establish cause and effect. Twin studies lead to validity issues. It is impossible to isolate and control all variables. Genetics DO NOT explain symptomology differences.

Selective Serotonin Reuptake Inhibitors (SSRIs)

classification of drugs that present the reuptake of serotonin. Class of drugs that are used as antidepressants for the treatment of MDD and anxiety disorders.

"Treatment etiology fallacy"

the mistaken belief that the effectiveness of a form of treatment indicates the cause of a disorder.

Aim of Chiao and Blizinsky (2010)

examine the association between cultural values of individualism-collectivism and the frequency of allele variations of the serotonin transporter gene 5-HTT relating to global variation in the prevalence of affective disorders

Bidirectional ambiguity

An uncertainty in whether or not x causes y, or if they are simply correlated.

For example, serotonin hypothesis

neurogenesis theory of depression

an explanation of depression that proposes that neurogenesis, the growth of new neurons, in the hippocampus stops during depression, and when it resumes, the depression lifts

niche-picking

tendency to actively choose environments that complement our heredity

Falconer model

assumes phenotype is made of influences such as genetics, shared environment and individual environment. This is made up of 3 influences: Genetic inheritance, shared common environment, and individual environment. (I=A+C+E)

. Hasler (2010)

argues against a single hypothesis of depression; he suggests that depression is a complex disorder that involves the interaction of a number of factors.

ABC'S of MDD

Affective symptoms: feelings of guilt and sadness; lack of enjoyment or pleasure in familiar activities or company;

Behavioural symptoms: passivity; lack of initiative;

Cognitive symptoms: frequent negative thoughts; low self-esteem; suicidal thoughts; irrational hopelessness; may also experience difficulties in concentration and inability to make decisions;

Somatic: loss of energy, insomnia, or hypersomnia; weight loss/gain; diminished libido.

How long must a person show symptoms of depression before they can diagnosed?

2 Weeks

Sullivan et al. (2000)

concluded that there is not a single gene that leads to depression, but rather that depression is the result of several genes that act together to produce a vulnerability to depression when other risk factors are present.

Cai et al (2015),

- found genetic sequences that seemed to be linked to depression

-gene which is important for energy-producing cell structures called mitochondria.

neurogenesis theory of depression

an explanation of depression that proposes that neurogenesis, the growth of new neurons, in the hippocampus stops during depression, and when it resumes, the depression lifts

HPA-axis hyperactivity

one of the most consistent biological findings in anxiety- and depression-related disorders.

-results in the over-secretion of cortisol.

Result of over secretion of cortisol

leads to reduced serotonin and other neurotransmitters in the brain, including dopamine, which has been linked to depression.

Malberg et al (2000)

treatments increased neurogenesis in the hippocampus and proposed that this increase is a mechanism to fight depression

Videbech and Ravnkilde (2004)

A hippocampal reduction could explain the common symptom of memory problems in patients with depression.

How many genes may be linked to depression?

Eleven genes - but we are not sure exactly the role they play.

What is the key advantage of using GWAS (genome wide association studies) as in the study by Cai et al (2015)?

Large sample size

Which of the following is evidence in support of the neurogenesis theory of depression?

Depressed patients have smaller hippocampi than the general population.

Cortisol and Depression

increased MAO-A Enzyme which breaks down serotonin

Cortisol impacts prefrtonal cortex and hippocampus