(2) Biomedical model, focus on diagnosis Flashcards
(52 cards)
1
Q
Guiding framework/model or paradigm are used to:
A
- Organize the available information about the onset and development of maladaptive behaviour
- Identify factors involved in psychological disorder and therapy
2
Q
What is the explanation for the biomedical model?
A
Explanation: psychological symptoms caused by biological factors
3
Q
What are the aims of the biomedical model?
A
identify the agent, or the mechanism
4
Q
What is the treatment of the biomedical model?
A
medication, surgery, shock therapy
5
Q
What did Kraepelin view abnormal behaviour as?
A
- View of disordered behaviour as due to organic causes (1856-1926)
- Emphasised the classification of abnormal behaviours into discrete disorders
- The view was of major importance in contributing to the emphasis of the medical approach to human problems
- Discrete disorders
- Certain symptom patterns occurred together regularly enough to be regarded as specific types of mental diseases
6
Q
After the 70s what was behaviour viewed as?
A
Behaviour was then considered to be a function of an interaction of biological, psychological and social variables, abnormal behaviour was due to organic causes started decreasing
7
Q
How does Schizophrenia develop?
A
heredity
8
Q
How does depression develop?
A
chemical imbalances within the brain
9
Q
How does anxiety develop?
A
defect within the autonomic nervous system
10
Q
How does dementia develop?
A
impairments in structures of the brain
11
Q
What are the risks of brain damage?
A
risk of psychopathology
12
Q
What is Neural plasticity?
A
Flexibility of the brain in making changes in organization/function, existing neural circuits can be modified/new circuits can be generated
13
Q
Who is at risk of brain defects?
A
Increased risk among the elderly due to age processing itself
14
Q
What can cause disorders?
A
A disorder can be caused by either too much or too little of a particular neurotransmitter
15
Q
How can hormonal imbalances effect brain disorders?
A
Hormones = chemical messengers secreted by a set of endocrine glands in our bodies
- Travel through our bloodstream affecting various parts of our body and brain
- CNS (central nervous system) linked to endocrine system
16
Q
What is an example of a chromosomal abnormality?
A
Chromosomal abnormalities: down’s syndrome
17
Q
what is physical deprivation associated with?
A
-Implicated in attention deficit disorder, depression, anxiety, eating disorders
18
Q
What is a humans basic needs?
A
food, oxygen, water, sleep, elimination of waste
19
Q
What are some examples of medical treatment?
A
- Brain stimulation therapies
- Surgery
- Pharmacological approaches
20
Q
What is insulin shock?
A
- Introduced by Sakel in 1933
- Used mainly for schizophrenia in the 1940s and 1950s
- Involved inducing repeated comas via insulin injection over weeks or months
- Risks included obesity, seizures, brain damage or even death (mortality rate 1-5%)
- Initially thought effective, but randomised controlled trials found that this was not the case (Ackner et al., 1957)
- Fell out of use by the 1960s, to be replaced by medication
21
Q
What is a Lobotomy?
A
- Prefrontal lobotomy was a common neurosurgical procedure: from 1935-55 over 40,000 were performed
- Involved severing the frontal lobes from the rest of the brain
- Developed by Egas Moniz who won the Nobel prize in 1949; later shot by former patient
- Popularised in the US by Walter Freeman
- Result: up to 4% death, inability to control impulses…
- Highly controversial
22
Q
The story of Rosemary Kennedy
A
- Slow development
- Private home tuition, good family life lead to improvement
- At 21 became frustrated, violent, ran away
- Prefrontal lobotomy wiped out speech and personality
23
Q
What -Brain stimulation therapies are currently used?
A
- Electroconvulsive therapy (ECT)
- Deep brain stimulation (DBS)
- Transcranial magnetic stimulation (TMS)
24
Q
What surgery is currently used?
A
Surgery: Neurosurgery for mental disorder (NMD)
-Pharmacological approaches
25
What is electroconvulsive therapy (ECT)?
- Inducing seizures under general anaesthesia & with muscle relaxants
- Passing electrical currents (150 volt for one second) through a patient’s head
- Every neurotransmitter system is affected by ECT, but not entirely clear how it works
- Each year around 100 000 patients treated in USA
- Now used with patients who have not responded to other treatments. Very effective for acute treatment
- Relatively safe; side effects include: headache, muscle ache, nausea and temporary memory loss
- High relapse rate (e.g. Kellner et al., 2006)
26
What is Transcranial magnetic stimulation (TMS)?
- Used for treatment-resistant depression and anxiety
- Electromagnetic coil sends magnetic pulses through the patient’s scalp into the brain
- These affect the function of neural circuits involved in mood, though unclear how
- Pulses are more focused than ECT: can stimulate brain regions involved in mood
- Meta-analysis by Slotema et al. (2010): TMS is effective for acute depression
27
What is Deep brain stimulation (DBS)?
- Involves implanting electrodes in specific parts of the brain to deliver electrical stimulation
- Used for severe, treatment-resistant depression and OCD
- Currently only used experimentally, but seems effective (e.g. Mayberg et al., 2005)
- Patients reported a “lifting of the void” and “connectedness”
- BUT DBS requires brain surgery, so should be a last resort
28
What are Neurosurgery for mental disorder (NMD)?
- Involves destroying or ablating minute areas in the brain that might contribute to mental illness.
- Much more focused than prefrontal lobotomy/leucotomy
- Used very rarely for treatment-resistant depression and OCD
- Adverse effects: transient headaches, but no change in skill or personality
29
What are antipsychotics?
- Psychotropic medication – any medication capable of affecting the mind, emotions & behaviour
- Antipsychotics - reduce delusions and hallucinations by blocking dopamine receptors
- Used for schizophrenia, mania, Tourette’s syndrome, and psychotic episodes
- Introduced in 1955; powerful impact on quality of treatment and interaction with patients
- Persistent use / high dosage = side effects (e.g. involuntary twitching); new expensive types less side effects
- Not serious side effects, however there are some
30
What are Antidepressants ?
- Several types, acting on different neurochemicals
- Most common: tricyclics and selective serotonin reuptake inhibitors (SSRIs)
- Equally effective
- Extremely popular; on the increase
- Some side effects (nausia, insomnia, sexual problems)
- Used in other disorders such as bulimia, anxiety disorders, OCD, chronic pain...
31
What are Anti-anxiety (anxiolytics)?
- Sedative and muscle-relaxing properties, but highly addictive
- Patients become drowsy, lethargic
- Efficacy and side effects vary between individuals
32
What is Lithium?
- Used for the treatment of bipolar disorder
- Lightest of metals; inorganic salts; unknown mechanism
- Dosage crucial (toxic), and very individual (close monitoring)
- Very effective (70-80%) in Bipolar
- Also effective sometimes with unipolar depression
- Side effects: thirst, gastro problems, weight gain, tremor and fatigue
33
Advantages of Biomedical approach
- Suggests a clear mechanism for most disorders: discredited ‘possessions’ or supernatural explanations
- Has been particularly effective in delivering insights into disorders with a clear biological cause, e.g. Alzheimer’s
- Absolves patients of responsibility, guilt and blame for their condition, since there is an objective biological explanation
- Drug treatment has revolutionised patient care: it is generally effective and is faster than other therapies
- Treatment based on the scientific method: in theory this means treatments should only be adopted if proven effective
- Can be quick but doesn’t treat the cause
34
Example: antidepressants
- One recent meta-analysis suggested SSRI anti-depressants were no more effective than placebo, except in severe cases (Kirschal., 2008)
- But another showed that the picture is more complicated: patients are either responders or non-responders (Gueorguieva et al. 2011) Gueorguieva et al. (2011) analysed data from 7 trials (2515 patients)
- 76% responded to SSRI/SNRIs, but 24% did not
- Looking at the whole sample, the treatment efficacy would not have been clear.
35
What are some Limitations to the biomedical approach?
- Historically, some treatments were unsafe and ineffective Even now, most treatments have side effects
- We still do not know exactly how medications work
- Most importantly, are we treating the underlying cause, or just symptoms? Are drugs used as a ‘chemical straitjacket’ to subdue patients rather than cure them?
- Usage in children controversial, as interactions with brain development are still unknown
- Drug development depends on rigorous methods and the integrity of researchers and drug companies
36
Example: antipsychotics in childhood
- Controversial rise in paediatric bipolar diagnosis, mostly in US: 40-fold increase between 1994 and 2003 (Moreno et al., 2007)
- Treated with atypical antipsychotic drugs
- Administration Report: 500,000 children prescribed these in US
- These drugs also frequently used for ADHD and conduct disorder
- Use is controversial: side effects (drowsiness, nausea, weight gain, diabetes…) and unknown effects on developing brain
- Increased risk of sudden cardiac death (Ray et al., 2009)
37
What is the DSM?
- Summarizes all the diagnoses
- Specifies what must be present to make a given diagnosis
- Organises the diagnoses into a classification system
- Constantly revised
- There have been several revisions since it was first published in 1952; currently in its fifth edition DSM-5
- Gradually including more mental disorders
- Some have been removed and are no longer considered to be mental disorders, e.g. homosexuality
38
DSM 1 (1952) 132 pages:
Contained vague criteria heavily influenced by psychoanalytic theory & an attempt to standardize diagnostic practices in use among military personnel in WWII.
39
DSM 2 (1968) 119 pages:
included some new disorders but it was not much different from first edition
40
What did DSM 1 and 2 have in common?
Vague and unclear criteria for the diagnostic classification - Lack of homogeneity within categories, low reliability and validity, for instance: Beck et al. (1962) found that 4 experienced clinicians using DSM-I to diagnose 153 patients agreed on their diagnosis only 54% of the time
41
DSM 3 (1980) 494 pages:
Lists and describes over 200 specific diagnostic categories or disorders
-Increase in the specificity of criteria: e.g. specified for HOW long the person must show the symptoms of the disorder to be given the diagnosis
42
What was wrong with DSM 3?
- Clinicians agreed on their diagnosis only about 70% of the time (Kirk & Kutchins, 1992)
- The criteria were still vague and required clinicians to make inferences about the client's symptoms
43
DSM 4 (1994):
Conservative approach: The reasons for changes in diagnosis would be explicitly stated and clearly supported by data
44
DSM 4 TR (2000) 943 pages:
Changes related to prevalence rates, course, and etiology Cultural and ethnic considerations included
45
Categorical approach:
Disorders are discrete –Are they really? What about comorbidity? Assumes that: All human behaviour can be divided into the categories of ‘healthy’ and ‘disordered’.
46
Dimensional approach:
Person’s behaviour is a product of deferring strengths and intensities of behaviour along several definable dimensions such as mood, emotional stability, etc.
47
DSM 5:
- The boundaries between many disorder categories are fluid over the life course – DSM-5 claims to be based on, or, at least is moving towards dimensional approach
- Symptoms assigned to one disorder may occur in many other disorders
- The client’s cultural and social context must be considered
- Making diagnoses requires clinical judgment, not just checking off the symptoms in the criteria
48
Diagnoses are made based on:
- The clinical interview
- DSM-5 text descriptions
- DSM-5 criteria
- Clinician judgment
- Need to take symptoms into account
49
Controversy over DSM 5
-Can lead to over-diagnosis and over-medication
50
Advantages of DSM
- Clarifies concepts
- Diagnosis have clinical utility - helps clinicians to determine prognosis and treatment plans
- Enables treatment – advantage for patient
- Enables research, etc
51
Disadvantages of DSM
- Overlap between disorders (comorbidity)
- Proliferation of disorders
- Human error
- Stigma associated with having a psychiatric diagnosis Etc.
- Stigma despite information being provided
- Stereotyping and labelling
52
International classification of diseases (ICD) – 10
- ICD-10 chapter V: Mental and behavioural disorders
- Part of the International Classification of Diseases
- Produced by the World Health Organization (WHO)
- Another commonly used guide (Europe and other parts of the world)
- DSM coding systems corresponds with the codes used in the ICD
- This not true always because the two publications are not revised synchronously
