lecture 2- causality in mental distress

What is causality?

• study of factors, mechanisms, relationships between factors and mechanisms that cause mental distress

• Causal attributions= everyday common-sense explanations of behaviour and its consequences.

• Causal models used to inform psychological assessment and clinical interventions

What causals factors are there for mental distress?

• relational:

  • Families, early experience, trauma and abuse

• Biological

  • Neurotransmitters, brain structure, genetics

• Social

  • Inequalities/poverty, gender/sexual orientation, ethnicity/ migrant status/ disability

Causality is probabilistic- many possible causes of distress. Over determined- can be explained in more than one way.

Causal influences are contingent, they interact with each other in way ways that are difficult to predict and identify.

How is causality established?

• covariation- if X is a cause of Y, then Y should occur more often than not when X is present

• Temporal precedence- the cause must precede mental distress in time

• Alternative explanations- must be able to exclude an alternative explanations for the causal relationship

• Logical connections- must be able to explain how X causes Y

What are sufficient and necessary causes?

Sufficient

• Y always occurs after X

• But Y can also occur in absence of X

Necessary

• Y never occurs without prior occurrence of X

• But X can also occur without leading to Y

What are insufficient causes?

• Y occurs only after X occurs with another variable (Z).

• Y does not occur when X occurs alone.

For mental distress, there are only insufficient causes.

And there are many insufficient causes that interact with each other.

What are difficulties with causal studies?

• many are cross sectional rather than longitudinal

• Difficult to study important influences prospectively. E.g. parenting impact may only become apparent years later

• Many influences occur over different time periods, different places, and interact with other variables.

• Impossible to include all important influences

• Practical and ethical limitations in manipulating influences, e,g, ethnicity, socio-economic status

• Sampling bas as many influences are sensitive

• Often not aware of all factors that lead to distress

• Researcher bias

• Social/cultural norms.

what methods are used to study causality?

• deductive approach- tests a theory of causality using predetermined variables

• inductive approach- explores experiences and links them to causal theory or devise new theories

• Epidemiological approach- studies determinants and distribution of health related topics.

Survey methods

• ask ppts directly about occurences of variables associated with distress

• Clinical interviews, self-report questionnaires

• Ppts can be sampled via quasi-random sampling

• Uses predefined range of variables of interest

Pros and cons of survey studies

Pros

• useful if large random samples are used together with valid and reliable clinical instruments

• Explores real variation in influences and mental distress

• Can be used longitudinally

Cons:

• data depends on questions being asked and preconceptions of the researcher

• Depends on what ppts are able and willing to tell the researhcers

• Some relevant mental health experiences mau be excluded if quasi-random is used

What are experiments?

• manipulate a variable to exxplore its effect on another

• Ppts sampled in random way

• Sample divided into experimental and control group

• Differences compared between groups in set of relevant measures

Pros and cons of experiments

Pros

• can provide strongest inference of causality

• High internal validity- controlled environment

Cons

• low external validity- difficult to generalise to real world

• Can’t control many confounding variables

• Convenience sampling- important causal influences may be missed

• Ethical and practical constraints

What are qualitative studies?

• deal with language, images, non-numerical data

• Doesnt test pre-conceived hypotheses

• E.g. interviews, focus groups, ethnography

• Inductive method

Pros and cons of qualitative studies

Pros

• explores how meaning of causal infleunces impact experiences

• Help identift causual order or temporal precedence

• Tell us somethinf about how different infleunces interact in mental distress

• Good for generating new hypotheses for quantiative

• Studying complex cases

Cons:

• cant be generalised

• Doesn’t test hypotheses

• Difficult to relate to quantitative findings

Pros and cons of

what are epidemiological studies?

• study determinants and distribution of health related topics

• frequently uses clinical info gathered by drs and pros

• studies how frequently diseases occur in different populations

• link variations in the prevalence of disease to other variables such as SES, lifestyle, employment history…

pros and cons of epistemological studies

pros

• provides most comprehensive picture of associations between demographic characteristics, lifestyle variables and distress

• can access in patient, clinic and hospital populations

• can be more effective than survey due to access to clinical info gathered

cons

• data based on diagnostic categories - lack validity

• prone to pre existing bias- difficult to measure

what is the biomedical model- BMM?

• assumes that individual differences in biological processes cause mental distress

• serotonin- involved in regulating functions e.g mood, sleep, appetite, decision making

• serotonin hypothesis (Coppen 1967) - low serotonin as cause for depression

• difficult to measure levels

why is establishing cause- effect relationships difficult?

• biological differences may result from mental distress

• Schmaal et al 2015- MRI data from large cross-cultural sample

• hippocampus volume reduced in pots with depression

• reduction correlated with number of depressive episodes

What is the relationship between causal beliefs and stigma?

Lebowitz & Appelabaum 2019 review

• BM views reduce blame from other and potentially self blame

• At the expense of perceptions of dangerousness and immutability

What is the relationship between causal beliefs and treatment preferences?

• likely influence treatment preferences

Read et al 2015

• those with BM beliefs thought of anti-depressants as more effective

• Sampling bias