theories of psychological disorders Flashcards
what is the medical model of psychological disorders?
symptoms are caused by an underlying factor
if we can design a test, we should be able to identify depression - not just the symptom
there are no objective tests of any psychological disorder
instead we assess clusters of symptoms
how common is co-morbidity?
caspi et al., 2018 assessed the life time comorbidity of psychological disorders in the dayton longitudinal stude
found that it is not uncommon to have 3-5 diagnoses
are psychological disorders heterogeneous
Even within well defined disorders there is considerable variation in the pattern of symptoms a given individual might display and still receive the same diagnoses (e.g schizophrenia)
what did harmer show about the cognitive effects of biological treatmetn
Healthy volunteers: Changes in cognitive bias (memory for positive adjectives) after 7 days of receiving reboxetine (selective norepinephrine reuptake inhibitor) or citalopram (SSRI).
murphy et al
A single dose of citalopram increased recognition of happy faces and decreased amygdala response to fearful faces
No effect on mood
harmer 2008
In healthy volunteers: no subjective mood effects
But changes in emotional information processing
Acute SSRI (e.g., a few hours)
Increased recognition of happy facial expressions
Increased attention to positive socially relevant stimuli
Increased fearful face recognition
Increased startle response
Chronic SSRI (e.g., 7 days)
More likely to see ambiguous facial expressions as
happy
Positive bias in personality adjective recall
Reduced perception of fearful, angry and disgusted
facial expressions
Reduced emotion-potentiated startle
rossler et al., 2004 behavioural treatment
D-cycloserine, a partial NMDA glutamatergic receptor agonist
Shown in animals to enhance extinction learning
Fear extinction in patients showing phobia
Two sessions of VR exposure therapy
Treatment / no treatment
Found that exposure therapy combined with D-cycloserine resulted in significantly larger reduction of fear of heights on all main outcome measures
bontempo et al., 2012 meta analysis behavioural therapy
SSRIs and cognitive therapies are effective in the treatment of anxiety and depression
Previous research suggests that both forms of treatments may work by altering cognitive biases and in the processing of affective information
Neuropsychopharmacology (2011) inhibition effects in cogntiive and pharmacological therapies
Investigated the effects of combining an SSRI with cognitive intervention on measures of affective processing bias and resilience to external challenge
62 participants randomly assigned treatment, either citalopram or placebo for 7 days
Completed either an active or controlled version of computerised cognitive bias training
Task participants who received both citalopram and the active cognitive bias training task showed a smaller alteration in emotional memory and categorisation bias
Other psychological treatments seem to inhibit the effects of each other
Replication: other studies support the finding that coadministration of antidepressant and cognitive training interventions may reduce the effectiveness of either treatment alone in terms of anxiety and depression relevant emotional processing.
If psychological disorders are common, harmful, and heritable why have they survived the process of natural selection?
Signal that someone is hurting/ unwell
Some symptoms could end up being helpful
Reactive defences to environmental stressors
Anxiety: defence against threat
Depression: defence against loss or social risk
what is the schizophrenia paradox
High prevalence
Individuals are less likely to have children or have fewer children
Why do we still see schizophrenia?
1% relatively high risk - exceeds common mutation rates
There must be some presumed force like an unknown advantageous phenotype or phenotypic quality that maintains the genotype
Anecdotal evidence: genius and psychosis linked e.g Einstein
murphy study schizotypy and creatives
what is trade off theory
Depression and anxiety develop from normal advantageous emotions
Psychological disorders involve a dysregulation, overactivation, or inappropriate evocation of a normal, adaptive mechanism.
E.g fear (maladaptive = anxiety)
Psychological disorders are (or were) in themselves adaptive.
Adaptive mechanism: averaged across individuals and environments, a mechanism which maximises survival and reproduction. (Nothing to do with subjective distress or quality of life!)
Group benefit - people with anxiety more likely to spot danger
Trade-off theory: Psychological disorders are (or were) side-effects of other adaptations
what is the mismatch explanation
Mismatch
Between environment we evolved to adapt to and modern environment
Explanation for rising incidence of psychological disorders
Well adapted for transient stress but not chronic prolonged stress
can we reduce stigma
Effects of chemical imbalance explanations Kemp et al., 2014
In individuals with a particular psychological condition as a result of a chemical imbalance
No effect of self-blame
Increased pessimism about prognosis, likelihood of getting better, reduced perceived ability to regulate emotional states
Increased belief in efficacy of pharmacotherapy vs psychotherapy
But the two have equal efficacy so not helpful
An Illness like any other (Kvaale et al., 2013)
Less blame
Increased perceptions of dangerousness, unpredictability, pessimism about recovery, desire for social distance, harsh punitive behaviour
Mental health professionals show lower empathy and lower endorsement of patient involvement in the planning of mental health services
Interventions can help reduce stigma Morgan et al, (2018).
Psychoeducation can reduce stigmatising attitudes: schools / national campaigns
Contact interventions - meeting individuals with a disorder, participating in activities together
Does this change behaviour as well as attitudes?
summary
Psychological disorders may be best thought of as ‘loose constructs’ – meaningful clusters of symptoms, but with much heterogeneity.
Research using more homogenous groups – e.g. with specific symptoms might help research to be more precise.
We still don’t know everything about why psychological disorders develop – but we do have insight into what makes symptoms worse – and, importantly, treatments that help..
