Schizophrenia

Positive - any behavioural excess 1. Hallucinations: These are unusual sensory experiences (visual, auditory, smell, touch or touch) 2. Delusions: There are irrational beliefs that have no basis in reality. Delusions can make a sufferer of schizophrenia behave in ways that make sense to them but seem bizarre to others. The most common are: · Delusions of persecution. This is the belief that they are being spied on or plotted against by others such as the government. · Delusions of grandeur. This is when a person believes they are an important historical or religious figure, such as the queen or the pope. negative - behavioural deficit. 1. Speech poverty (Alogia): This is a decrease in speech fluency and productivity. They produce fewer words in a given time on a task of verbal fluency (e.g. name as many animals as you can in 1 minute). This is not due to less verbal ability than people without schizophrenia, but more a difficulty spontaneously producing them. Patients will often slur their responses, not pronouncing consonants clearly and their words might trail off into a whisper. 2. Avolition: A reduction of interests and desires as well an inability to initiate and persist in goal-directed behaviour. For example, sitting in the house for hours every day, doing nothing. Avolition is distinct from poor social functioning, which can be the result of other circumstances (e.g. having no friends and family available to have social contact with). To be classed as avolition, there must be a reduction in self-initiated involvement in activities that are available to the patient.

the consistency in the diagnosis. whether there is agreement in the diagnosis of schizophrenia by different psychiatrists across time and cultures. stability of diagnosis over time given no change in symptoms This is known as inter-rater reliability. Reliability can also be seen in whether diagnostic tests are consistent on different occasions. This is known as test-retest reliability.

There is criticism that the DSM and ICD tools are routinely used with a high level of reliability by mental health clinicians. Cheniauxasked two psychiatrists to independently diagnose 100 patients using both the DSM and the ICD. Inter-rater reliability was poor, for example, using the DSM, one psychiatrist diagnosed 26 patients with schizophrenia whilst the other only diagnosing 13. This a weakness of the diagnostic systems as they failed to produce consistent results and therefore shows that the reliability of diagnosing schizophrenia is poor. However, recent research has found that reliability for diagnosing Schizophrenia has improved. Osorio et al (2019) reported excellent reliability for the diagnosis of Schizophrenia using DSM-5. Pairs of interviewers achieved inter-rater reliability =.97 and test-retest reliability of =.92. This suggests that the diagnostic system is consistently applied and therefore has good reliability. Furthermore, even if the reliability of the classification systems are not perfect, they do provide clinicians with a common language, permitting communication of research ideas and findings, which may ultimately lead to a better understanding of the disorder and more effective treatments

co-morbidity is where two conditions co-exist in the same individual at the same time so a person with schizophrenia might also at the same time be suffering from another condition, e.g. personality disorder, depression, alcoholism, etc an issue for the reliability of the diagnosis of schizophrenia. If a sufferer can experience simultaneous disorders this suggests that schizophrenia may not actually be a separate disorder. This could lead to different medical professionals giving different diagnoses of the same patient.

There is a large body of evidence to suggest that many sufferers do also have issues of substance abuse. Buckley found that around 50% of patients with schizophrenia also have depression or substance abuse. Alcohol, cannabis and cocaine are substances that can be abused by people with schizophrenia (possibly as a way of self-medicating) and not only does such co-morbid substance abuse make a reliable diagnosis of schizophrenia difficult to achieve, it also leads to lower levels of functioning, increased hospitalisations and lower compliance with medication, which makes effective treatment more difficult to achieve. This is a strength because it demonstrates the complexities involved in giving a reliable diagnosis if the person with schizophrenia is also using recreational drugs. Sufferers who use recreational drugs may find it difficult to achieve a reliable diagnosis as it’s difficult to know what symptoms are a direct effect of having schizophrenia and what are the symptoms of substance abuse. (Additionally) Jeste et al., (1996) states that those sufferers of schizophrenia with co-morbid conditions are excluded from research and yet form the majority of patients, which suggests that research findings into the causes of schizophrenia may not be based on reliable research as the samples used are not consistent.

The extent to which the diagnostic system reflects beliefs about what is viewed as normal and acceptable in Western, predominately white cultures. Culture bias reduces the validity of the diagnostic system. Both the ICD and DSM were developed by Western clinicians and are criticised for lacking cultural relativism. Therefore, people who show behaviours such as hearing voices, which may be normal in their own culture, are sometimes classified as having schizophrenia. Culture bias can also affect the reliability of the diagnostic system. Research suggests there is a significant variation between cultures when it comes to diagnosing schizophrenia. Copeland (1971) gave 134 US and 194 British psychiatrists a description of a patient. 60% of the US psychiatrists diagnosed schizophrenia, but only 2% of British ones did, showing diagnosis was unreliable across different cultures.

Research suggests that the diagnosis of schizophrenia is affected by culture bias.Pinto and Jones reported that in Haiti some people believe that voices are communications from ancestors. British people of African – Caribbean origin are up to nine times more likely to receive a diagnosis than white British people, although people living in African – Caribbean countries are not, ruling out a genetic vulnerability. This is a weakness of the diagnostic system because it highlights that the difference in diagnostic statistics of some cultural groups is due to the biased overinterpretations of symptoms by some psychiatrists. However the higher statistics could represent the effects of the poorer housing, higher rates of unemployment and social isolation that are more commonly experienced by minority groups such as African-Caribbean groups. A* - How can you use the research findings above from Copeland (1971) (as A03 rather than A01) to further demonstrate an issue of reliability when diagnosing schizophrenia and that this could be due to culture bias/ethnocentric bias?

This is the extent to which the methods used to measure schizophrenia are accurately measuring schizophrenia. For example, the patient may have hallucinations but is not suffering with schizophrenia (symptom overlap and comorbidity) or it may be that psychiatrists are misinterpreting the behaviour of the patient (gender/culture bias). Additionally, different assessment systems (ICD/DSM) may arrive at completely different diagnoses. We can assess validity by using predictive validity - if a diagnosis leads to successful treatment, then diagnosis is seen as valid The research findings on whether the diagnosis of schizophrenia is valid are very mixed. Some researchers report that when you match patients diagnosed with schizophrenia to the DSM criteria there is a good correlation (Hollis, 2000), suggesting that diagnosis is valid. However, two diagnosed patients can differ greatly on the precise symptoms each displays (for example, one showing delusions, but the other not – but they both have a diagnosis of schizophrenia). This suggests that a single label of schizophrenia is not valid. Perhaps it is more valid to use the presence or absence of positive and negative symptoms to distinguish different forms of schizophrenia, as the DSM-V does.

A threat to the validity of diagnosing schizophrenia is highlighted by the fact that in the same way that people diagnosed with schizophrenia 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. This is a problem because a diagnosis therefore, has little predictive validity because some people never appear to recover from the disorder, while many do. What does appear to influence outcome is more to do with gender and psycho-social factors such as social skills, academic achievement and family tolerance of schizophrenic behaviour.

symptoms of schizophrenia also found in other disorders hard to diagnose

occurs when the diagnosis is dependent on the gender of an individual, the diagnostic criteria may be gender based or clinicians may base their judgements on stereotypical beliefs about gender. statistically since 1980s men are diagnosed w schizophrenia more oftn than womne, maybe due to genetic factors women are genetically less vulnerable than men. howveer, seems more likely that women are undiagnosed bc theyre more likely to have support around them so they function better than men cotton found that in patientsw schzio, female patients function better than male. suggests their interpersonal functioning may bias clinicians to underdiagnose schizophrenia in women

Research suggests symptom overlap can cause issues when accurately and reliably diagnosing schizophrenia. Ophoff found a genetic overlap between bipolar disorder and schizophrenia. Three of the seven gene locations on the genome associated with schizophrenia were also associated with bipolar disorder. Both schizophrenia and bipolar disorder involve positive symptoms (such as delusions) and negative symptoms (such as avolition) This highlights the problem when trying to distinguish schizophrenia from other illnesses and in terms of classification this suggests that schizophrenia and bipolar disorder may not be two different conditions but variations of single condition.Furthermore Ellason and Ross point out that, not only is there a great deal of overlap between SZ and bipolar disorder, but people with another disorder called ‘Dissociative Identity Disorder’ (DID) actually have more symptoms of schizophrenia than people diagnosed as being schizophrenic. This is a problem as it brings into question whether SZ, bipolar disorder and DID are separate disorders at all or part of the same spectrum.

A biological explanation of schizophrenia involves neural correlates. These are measurements of the structure or function of the brain that correlate with an experience (in this case schizophrenia). These correlates have allowed abnormalities within specific brain areas to be associated with the development of schizophrenia. Dopamine Hypothesis: Knowledge (A01) biological explanation of schizophrenia is the ‘dopamine hypothesis’. This biochemical explanation suggests that the positive symptoms of schizophrenia are the result of the overactive transmission of the neurotransmitter dopamine. Sufferers of Sz are thought to have abnormally high numbers of D2 receptors on receiving neurons, resulting in more dopamine binding and therefore more neurons firing. Dopamine neurons play a key role in guiding attention, so disturbances in this process may well lead to the problems relating to attention, perception and thought found in people with schizophrenia. For example, an excess of dopamine has been found in the Broca’s area. As the Broca’s area is responsible for speech production, an excess of dopamine in this area may be responsible for auditory hallucinations. Recent versions of the dopamine hypothesis have focused on abnormal dopamine levels in the pre-frontal cortex (outer layer of the brain). For example low levels in the prefrontal cortex (responsible for thinking and decision making) are linked to the negative symptoms of schizophrenia. Therefore, it appears that both high and low levels of dopamine, in different brain regions, are involved in schizophrenia.