schizo Flashcards
THE NATURE OF SCHIZOPHRENIA
Schizophrenia is a type of psychosis, a severe mental disorder in which thoughts and emotions are so impaired that contact is lost with external reality.
Schizophrenia is the most common psychotic disorder, affecting about 1% of the population at some point in their lifetime, although many continue to lead normal lives after diagnosis and subsequent treatment.
Schizophrenia is most often diagnosed between the ages of 15 and 35, with men and women affected equally.
Someone diagnosed with schizophrenia would characteristically experience delusions (a belief in something that is not, nor could be, true) and hallucinations (experiencing stimuli that are not present).
There are many symptoms of the disorder, although not every patient displays all the symptoms.
Diagnosis & classification of schizophrenia (these two things are interlinked)
To diagnose a disorder, we must be able to distinguish between disorders
Diagnosis means identifying clusters of symptoms that occur together
We then classify these symptoms as one disorder
A disorder can then be diagnosed by identifying the symptoms
There are two major systems for classification of mental disorders
World Health Organisation’sinternational classification of diseases (ICD-10, version 11 currently,) and
American Psychiatric Association’s Diagnostic & Statistical Manual (DSM-5)
There are some differences between them egin DSM, one positive symptom (see next slide)must be present for diagnosis whereas in ICD, two or more negative symptoms are sufficient
NB Previously recognised subtypes of schizophrenia have now been dropped eg paranoid schizophrenia, because it has been found that individuals will not necessarily display the exact same symptoms a few years on
Positive symptoms:
The symptoms of schizophrenia are typically divided into positive symptoms and negative symptoms.
Positive symptoms are those that appear to reflect an excess or distortion of normal functions. They include the following:
- Hallucinations
- Delusions
Disorganised speech - Grossly disorganised or catatonic behaviour
Hallucinations
bizarre, unreal perceptions of the environment that are usually auditory (hearing voices that other people can’t hear) but may also be visual (seeing lights, objects or faces that other people can’t see), olfactory (smelling things that other people cannot smell) or tactile (e.g. feeling that bugs are crawling on or under the skin or something touching the skin).
Many schizophrenics report hearing a voice or several voices, telling them to do something (such as harm themselves or someone else) or commenting on their behaviour.
Delusions
bizarre beliefs that seem real to the person with schizophrenia, but they are not real.
Sometimes these delusions can be paranoid (i.e. persecutory) in nature.
This often involves a belief that the person is being followed or spied upon by someone.
They may believe that their phone is tapped or that there are video cameras hidden in their home.
Delusions may also involve inflated beliefs about the person’s power and importance (delusions of grandeur).
For example, the individual may believe they are famous or have special powers or abilities.
An individual may also experience delusions of reference, when events in the environment appear to be directly related to them - for example, special personal messages are being communicated through the TV or radio.
Disorganised speech
is the result of abnormal thought processes, where the individual has problems organising his or her thoughts and this shows up in their speech.
They may slip from one topic to another (derailment), even in mid-sentence, and in extreme cases their speech may be so incoherent that it sounds like complete gibberish - something that is often referred to as “word salad’”
- Grossly disorganised or catatonic behaviour
includes the inability or motivation to initiate a task, or to complete it once it is started, which leads to difficulties in daily living and can result in decreased interest in personal hygiene.
The individual may dress or act in ways that appear bizarre to other people, such as wearing heavy clothes on a hot summer’s day.
Catatonic behaviours are characterised by a reduced reaction to the immediate environment, rigid postures or aimless motor activity.
Negative symptoms:
Involve the loss of usual abilities & experience
- Speech poverty (alogia)
- Avolition
Anhedonia - Affective flattening
Speech poverty (alogia)
characterised by the lessening of speech fluency and productivity.
this is thought to reflect slowing or blocked thoughts.
Patients who display speech poverty display a number of characteristic signs.
They may produce fewer words in a given time on a task of verbal fluency (e.g. name as many animals as you can in one minute).
This is not a matter of not knowing as many words as non-schizophrenics, but more a difficulty of spontaneously producing them.
Speech poverty may also be reflected in less complex syntax, e.g. fewer clauses, shorter utterances, etc.
This type of speech appears to be associated with long illness and earlier onset of the illness.
- Avolition
a reduction of interests and desires as well as an inability to initiate and persist in goal-directed behaviour (e.g. sitting in the house for hours every day, doing nothing).
Avolition is distinct from poor social function or disinterest, which can be the result of other circumstances.
For example, an individual may have no social contact with family or friends because they have none, or communication with them is difficult.
This would not, however, be considered avolition, which is specified as a reduction in self-initiated involvement in activities that are available to the patient.
- Affective flattening
a reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language.
Compared to controls without this symptom, individuals show fewer body and facial movements and smiles, and less co-verbal behaviour, i.e. those movements of the hands, head and face that usually accompany speech.
When speaking, patients may also show a deficit in prosody, ie paralinguistic features (such as intonation, tempo, loudness and pausing) that provide extra information that is not explicitly contained in a sentence, and which gives cues to the listener as to emotional or attitudinal content and turn-taking.
- Anhedonia
a loss of interest or pleasure in all or almost all activities, or a lack of reactivity to normally pleasurable stimuli.
It may be pervasive (ie, all-embracing) or it may be confined to a certain aspect of experience.
Physical anhedonia is the inability to experience physical pleasures such as pleasure from food, bodily contact and so on.
Social anhedonia is the inability to experience pleasure from interpersonal situations such as interacting with other people.
Because social anhedonia overlaps with other disorders (such as depression), whereas physical anhedonia does not, the latter is considered a more reliable symptom of schizophrenia (Sarkar et al, 2010).
RELIABILITY
Diagnostic reliability means that a diagnosis of schizophrenia must be repeatable, i.e. clinicians must be able to reach the same conclusions at two different points in time (test-retest reliability), or different clinicians must reach the same conclusions (inter-rater reliability).
Inter-rater reliability is measured by a statistic called a kappa score.
A score of 1 indicates perfect inter-rater agreement; a score of 0 indicates zero agreement.
A kappa score of 0.7 or above is generally considered good.
In the DSM-V field trials (Regier et al., 2013), the diagnosis of schizophrenia had a kappa score of only 0.46.
Cultural differences in diagnosis:
Research suggests there is a significant variation between countries when it comes to diagnosing schizophrenia, i.e. culture has an influence on the diagnostic process.
Copeland (1971) gave 134 US and 194 British psychiatrists a description of a patient.
Sixty-nine per cent of the US psychiatrists diagnosed schizophrenia, but only 2% of the British ones gave the same diagnosis.
One of the main characteristics of schizophrenia, ‘hearing voices, also appears to be influenced by cultural environment.
Luhrmann et al. (2015) interviewed 60 adults diagnosed with schizophrenia - 20 each in Ghana, India and the US.
Each was asked about the voices they heard.
Strikingly, while many of the African and Indian subjects reported positive experiences with their voices, describing them as playful or as offering advice, not one American did.
Rather, the US subjects were more likely to report the voices they heard as violent and hateful - and indicative of being ‘sick’
Luhrmann suggests that the “harsh, violent voices so common in the West may not be an inevitable feature of schizophrenia.
Rosenhans study of the unreliability of the diagnosis of mental disorder:
The unreliability of diagnosis was highlighted by Rosenhan’s famous study in which ‘normal’ people presented themselves to psychiatric hospitals in the US claiming they heard an unfamiliar voice in their head saying the words ‘empty, ‘hollow’ and ‘thud’ (Rosenhan, 1973).
They were all diagnosed as having schizophrenia and admitted.
Throughout their stay, none of the staff recognised that they were not actually displaying symptoms of schizophrenia.
In a follow-up study, Rosenhan warned hospitals of his intention to send out more ‘pseudopatients.
This resulted in a 21% detection rate, although none actually presented themselves!
Within the study Rosenhan ran a small field experiment in four of the hospitals.
Either a pseudopatient or a young lady approached a staff member and asked questions such as: ‘Pardon me, Mr/Mrs/Dr X, could you tell me when I will be eligible for grounds privileges?’
The pseudopatient did this as normally as possible and avoided asking any particular person more than once in a day.
Only 4% of the psychiatrists and 0.5% of the nurses stopped; 2% in each group paused and chatted
When the young lady approached staff members and asked them the same questions, they all stopped and answered her questions, maintaining eye contact.
VALIDITY:
Gender bias in diagnosis:
Gender bias in the diagnosis of schizophrenia is said to occur when accuracy of diagnosis is dependent on the gender of an individual.
The accuracy of diagnostic judgements can vary for a number of reasons, including gender-biased diagnostic criteria or clinicians basing their judgements on stereotypical beliefs held about gender.
For example, critics of the DSM diagnostic criteria argue that some diagnostic categories are biased towards pathologising one gender rather than the other.
Broverman et al. (1970) found that clinicians in the US equated mentally healthy ‘adult’ behaviour with mentally healthy ‘male’ behaviour.
As a result, there was a tendency for women to be perceived as less mentally healthy.
Symptom overlap:
Despite the claim that the classification of positive and negative symptoms would make for more valid diagnoses of schizophrenia, many of these symptoms are also found in many other disorders, such as depression and bipolar disorder.
This problem is referred to as symptom overlap.
For example, Ellason and Ross (1995) point out that people with dissociative identity disorder (DID) actually have more schizophrenic symptoms than people diagnosed as being schizophrenic!
Most people who are diagnosed with schizophrenia have sufficient symptoms of other disorders that they could also receive at least one other diagnosis (Read, 2004).
Co-morbidity:
It refers to the extent that two (or more) conditions co-occur.
Psychiatric co-morbidities are common among patients with schizophrenia.
These include substance abuse, anxiety and symptoms of depression. For example, Buckley et al. (2009) estimate that co-morbid depression occurs in 50% of patients, and 47% of patients also have a lifetime diagnosis of co-morbid substance abuse.
Schizophrenia and obsessive-compulsive disorder (OCD) are two distinct psychiatric conditions.
Roughly 1% of the population develop schizophrenia, and roughly 2-3% develop OCD.
Since both are fairly uncommon, we would expect that only a few people with schizophrenia would develop OCD and vice versa.
However, evidence suggests that the two conditions appear together more often than chance would suggest. A meta-analysis by Swets et al. (2014) found that at least 12% of patients with schizophrenia also fulfilled the diagnostic criteria for OCD and about 25% displayed significant obsessive-compulsive symptoms.
EVALUATION/DISCUSSION OF RELIABILITY:
Lack of inter-rater reliability:
Unreliable symptoms:
A comment on cultural differences in the diagnosis of schizophrenia:
Lack of inter-rater reliability:
Despite the claims for increased reliability in DSM Ill (and later revisions), over 30 years later there is still little evidence that DSM is routinely used with high reliability by mental health clinicians.
For example, Whaley (2001) found inter-rater reliability correlations in the diagnosis of Scizophrenia as low as 0. 11.
Further problems with the inter-rater reliability of the diagnosis of schizophrenia are illustrated in the Rosenhan study
This suggests that, because psychiatric diagnosis lacks some of the more objective measures enjoyed by other branches of medicine, it inevitably faces additional challenges with inter-rater reliability.
Unreliable symptoms:
For a diagnosis of ‘schizophrenia’, only one of the characteristic symptoms is required ‘if delusions are bizarre’
However, this creates problems for reliability of diagnosis.
When 50 senior psychiatrists in the US were asked to differentiate between ‘bizarre’ and ‘non-bizarre’ delusions, they produced inter-rater reliability correlations of only around 0.40 (Mojabi and Nicholson, 1995).
The researchers concluded that even this central diagnostic requirement lacks sufficient reliability for it to be a reliable method of distinguishing between schizophrenic and non-schizophrenic patients.
A comment on cultural differences in the diagnosis of schizophrenia:
Research (e.g. Barnes, 2004) has established cultural, and racial, differences in the diagnosis of schizophrenia.
However, the prognosis for members of ethnic minority groups may be more positive than for majority group members.
The ethnic culture hypothesis predicts that ethnic minority groups experience less distress associated with mental disorders because of the protective characteristics and social structures that exist in these cultures.
Brekke and Barrio (1997) found evidence to support this hypothesis in a study of 184 individuals diagnosed with schizophrenia or a schizophrenia-spectrum disorder.
This sample was drawn from two non-white minority groups (African Americans and Latinos) and a majority group (white Americans).
Consistent with the predictions of the ethnic culture hypothesis, they found that non-minority group members were consistently more symptomatic than members of the two ethnic minority groups.
EVALUATION/DISCUSSION OF VALIDITY:
Research support for gender bias in diagnosis
The consequences of co-morbidity:
Differences in prognosis
Research support for gender bias in diagnosis
Loring and Powell (1988) found evidence of gender bias among psychiatrists in the diagnosis of schizophrenia.
They randomly selected 290 male and female psychiatrists to read two case vignettes of patients’ behaviour.
These psychiatrists were asked to offer their judgement using standard diagnostic criteria.
When the patients were described as ‘males’ or no information was given about their gender, 56% of the psychiatrists gave a diagnosis of schizophrenia.
However, when the patients were described as ‘female’, only 20% were given a diagnosis of schizophrenia.
This gender bias was not as evident among the female psychiatrists, suggesting that diagnosis is influenced not only by the gender of the patient but also the gender of the clinician.
The consequences of co-morbidity:
A number of studies have examined single co-morbidities with schizophrenia, but these studies have usually involved only relatively small sample sizes.
By contrast, Weber et al. (2009) looked at nearly 6 million hospital discharge records, finding evidence of many co-morbid non-psychiatric diagnoses.
Many patients with a primary diagnosis of schizophrenia were also diagnosed with medical problems including asthma, hypertension and type 2 diabetes.
The authors concluded that the very nature of a diagnosis of a psychiatric disorder is that patients tend to receive a lower standard of medical care, which in turn adversely affects the prognosis for patients with schizophrenia.
Differences in prognosis:
In the same way that people diagnosed as schizophrenic rarely share the same symptoms, likewise there is no evidence that they share the same outcomes.
The prognosis for patients diagnosed with schizophrenia varies with about 20% recovering their previous level of functioning, 10% achieving significant and lasting improvement, and about 30% showing some improvement with intermittent relapses.
A diagnosis of schizophrenia, therefore, has little predictive validity - some people never appear to recover from the disorder, but many do.
What does appear to influence outcome, therefore, is more to do with gender (Malmberg et al., 1998) and psychosocial factors such as social skills, academic achievement and family tolerance of schizophrenic behaviour (Harrison et al., 2001).
Biological explanations:
emphasise the role of inherited factors and dysfunction of brain activity the development of a behaviour or mental disorder
Neural correlates:
Changes in neuronal events and mechanisms that result in the characteristic symptoms of a behaviour or mental disorder.
GENETIC FACTORS:
Family studies:
Twin studies:
Adoption studies:
Family studies:
Family studies have established that schizophrenia is more common among biological relatives of a person with schizophrenia, and that the closer the degree of genetic relatedness, the greater the risk.
For example, in Gottesman’s study, children with two schizophrenic parents had a concordance rate of 46%, children with one schizophrenic parent a rate of 13%, and siblings (where a brother or sister had schizophrenia) a concordance rate of 9%.
