Schizophrenia Flashcards
Schizophrenia
Schizophrenia is a serious mental psychotic disorder characterised by a profound disruption of cognition and emotion. It is so severe, that it affects a person’s language, thought and perception, emotions and even their sense of self. It is suffered by approximately 1% of the population.
What kind of disorder is SZ
Schizophrenia is a psychotic rather than neurotic disorder – the term psychotic refers to serious mental issues causing abnormal thinking and perceptions and also the fact that people lose touch with reality and even their sense of self. Many people who suffer from schizophrenia end up homeless or hospitalised. It is not uncommon for a person suffering with SZ to commit or attempt suicide.
Classification systems used to diagnose SZ
Two classification systems are used to diagnose schizophrenia.
1. The DSM 5(The Diagnostic and Statistical Manual of Psychiatric Disorders) – devised by the American Psychological Association (APA) – the DSM is currently now in its 5th edition.
- The ICD 11 (The International Classification of Diseases) – devised by the World Health Organisation (WHO) - the ICD is currently in its 11 th edition
The DSM is thus used in America and the ICD is used in Europe and the other parts of the world too.
How do the classification systems diagnose SZ
DSM 5 states that you need to show at least two or more positive symptoms such as hallucinations or delusions (or one positive and one negative) for a period of one month (as well as extreme social withdrawal for at least six months) to be diagnosed with schizophrenia
The ICD 11 states you need to show one positive and one negative symptom (or two negative symptoms) for at least one month to be diagnosed with schizophrenia.
Also both the ICD and DSM recognises that there are subtypes of schizophrenia (such as Catatonic Schizophrenia, Paranoid Schizophrenia) but both manuals have deleted these subtypes of schizophrenia as it made diagnosis more complex and had little effect on the treatments.
Positive symptoms of SZ (hallucinations)
Positive symptoms are those that appear to reflect an excess or distortion of normal functions and can be seen below:
- Hallucinations – these are sensory experiences of stimuli that have either no basis in reality or are distorted perceptions of things that are there
Auditory (hearing) hallucinations: this is when the person will experience hearing voices making comments or talking to them in their head normally criticising them.
Visual (seeing) hallucinations: seeing things which are not real e.g. distorted facial expressions on animals or people
Olfactory (Smelling) hallucinations: smelling things which are not real e.g. a person could be smelling disinfectant which is not real
Tactile (touching and feeling) hallucinations: touching things which are not there for example, bugs are crawling on your skin
Positive symptoms of SZ (delusions)
- Delusions – also known as paranoia – these are irrational, bizzare beliefs that seem real to the person with SZ. These can take a range of forms. Common delusions involve being an important historical, religious or political figure such as Jesus or Napoleon. Delusions also may involve being persecuted perhaps by government, aliens or even superpowers. Delusions may involve the body – sufferers may believe that they or part of them is under external control. Some delusions can lead to aggression but this is not often.
Positive symptoms of SZ (disorganised speech and catatonic behaviour)
- Disorganised speech – this 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 – this is often referred to as ‘word salad’. (this symptom is diagnosed in the DSM but not ICD – extra symptom)
- Grossly disorganised or catatonic behaviour – includes the inability or motivation to initiate or even complete a task – this can lead to problems of personal hygiene or the person could be over active and doing loads of different activities simultaneously. The person may dress in a bizarre way such as wearing warm clothes on a hot summer’s day. Catatonia refers to adopting rigid postures or aimless repetition of the same behaviour. (this symptom is diagnosed in the DSM but not ICD – extra symptom)
Negative symptoms of SZ (speech poverty and avolition)
Negative symptoms of SZ are those that appear to reflect a reduction or loss of normal functions which often persist even during periods of low (or absent) positive symptoms.
- Speech Poverty (Alogia): SZ is characterised by changes in patterns of speech – meaning the emphasis is on the reduction in the amount and quality of speech. This is sometimes accompanied by a delay in the sufferer’s verbal responses during conversation. 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: this can sometimes be called apathy – and can be described as finding it difficult to begin or keep up with goal-directed activity, i.e. actions performed in order to achieve a result. Sufferers of SZ often have sharply reduced motivation to carry out a range of activities. Andreason (1982) identified these signs of avolition; poor hygiene and grooming, lack of persistence in work or education and lack of energy
Negative symptoms of SZ (affective flattening and anhedonia)
- Affective flattening: a reduction in the range and intensity of emotional expression, including facial expression, voice tone, eye contact and body language. Individuals who are schizophrenic have fewer body and facial movements and smiles, and less co-verbal behaviour. When speaking, patients may also show a deficit in prosody e.g. intonation, tempo, loudness and pausing
Anhedonia – a loss of interest or pleasure in all or most activities, or a lack of reactivity to normally pleasurable stimuli. Physical anhedonia is the inability to experience physical pleasures such as pleasure from food, bodily contact etc. Social anhedonia is the inability to experience pleasure from interpersonal situations such as interacting with other people (extra symptom)
Problems associated with the classification and diagnosis of SZ (reliability)
- Reliability – consistency of a measuring instrument (e.g. the DSM or ICD). An example of reliability is inter-rater reliability – this is when two or more diagnosticians agree with the same diagnosis for the same individual – diagnosis would be done separately. Whaley (2001) found the interrater reliability between diagnosticians as low as +0.11 (using the DSM). Another more recent study that also showed low inter rater reliability amongst diagnosticians was carried out by Cheniaux et al (2009). In this study, they had two psychiatrists independently diagnose 100 schizophrenic patients using both ICD and DSM criteria. Inter-rater reliability was poor with one psychiatrist diagnosing 26 with SZ according to DSM and 44 according to ICD and the other psychiatrist diagnosing 13 according to DSM and 24 according to ICD. This poor reliability is a weakness of diagnosis of SZ
Problems with classification and diagnosis of SZ (validity)
- Validity – the extent to which we are measuring what we intend to measure. In other words, are we diagnosing schizophrenia correctly based on the symptoms used in the manuals. This can be assessed using criterion validity which is when different assessment systems arrive at the same diagnosis for the same patient – (e.g. both using ICD and DSM – the patient is seen as schizophrenic). According to Cheniaux’s study we can see the SZ is much more likely to be diagnosed using ICD than DSM suggesting that SZ is either over diagnosed in ICD and under diagnosed in DSM. Either way, this problem is a sign of poor validity
Problems with classification and diagnosis of SZ (co-morbidity)
- Co-morbidity – the idea that two or more mental disorders (or conditions) occur together at the same time with the same person. If this is the case, then we can question the validity of diagnosis for schizophrenia. Infact, schizophrenia is commonly diagnosed with other conditions.
In one review Buckley et al. (2009) concluded that around half of the patients with SZ also have a diagnosis of depression (50%) or substance abuse (47%). Post- traumatic stress disorder also occurred in 29% of cases and OCD in 23% of cases.
This poses a challenge for both classification and diagnosis of SZ. In terms of diagnosis, if half the patients are diagnosed with both SZ and depression, this suggests that we are not able to distinguish between both disorders very well.
Problems with classification and diagnosis of SZ (symptom overlap)
- Symptom overlap – this means that there is considerable overlap between the symptoms of SZ and other conditions such as depression and bipolar disorders. For example, a person can show a symptom of SZ and this symptom will also be in another disorder. For example, Ellason and Ross (1995) point out that people with DID (Dissociative Identity Disorder) actually having more schizophrenic symptoms than people diagnosed with SZ. In fact, most people diagnosed with SZ have sufficient symptoms of other disorders that they could also receive at least one other diagnosis (Read, 2004)
This overlap would question the validity of the classification and diagnosis of SZ. For example, under the ICD, a patient may be diagnosed with SZ but under the DSM the same person will be diagnosed with bipolar disorder – because of this overlap, this suggests that SZ and bipolar may not be two disorders but one
Problems with classification and diagnosis of SZ (gender bias in diagnosis)
Longenecker et al (2010) reviewed SZ studies since the 1980s and found men more likely to be diagnosed than women. Is it because men more genetically vulnerable than women? There could be a gender bias in diagnosis as women seem to function better than men having good family relationships and more likely to work (Cotton 2009). Therefore it is less likely to be diagnosed with SZ because women showing better interpersonal function than men. Thus, there seems to be a gender bias in diagnosis of SZ with more males getting diagnosed than females
Problems with classification and diagnosis of SZ (cultural bias in diagnosis)
African American and English people of Afro Caribbean origin are nine times more likely to be diagnosed with SZ. (Pinto and Jones, 2008)Why?
It may be because positive symptoms of SZ such as auditory hallucinations may be acceptable in Africa because of cultural beliefs in communication with ancestors (e.g. hearing their dead ancestors talking to them) which are acceptable and not warranted to a diagnosis in Africa (as SZ rates low in Africa).
However in the UK, this is more likely to be seen as a positive symptom of SZ.
Or, could it be that in Western cultures, we doubt the honesty of black people (Escobar, 2012)
Advantages of classification and diagnosis of SZ (3p)
- Communication shorthand: a patient with a mental disorder often has numerous symptoms. It is simpler to incorporate these symptoms into a single diagnosis and this makes communication between mental health professionals much easier
- Treatment: treatments are often specific to certain disorders e.g. symptoms of schizophrenia respond well to certain anti-psychotic drugs but not anti-anxiety. A reliable diagnosis can point to a therapy that will alleviate symptoms.
- Although there is variation, there are many underlying biological abnormalities seen in people with schizophrenia. It is hoped that a greater understanding of these abnormalities will lead to even more effective treatment.
Biological explanations consist of what
Biological explanations of schizophrenia are based on two factors: the genetic basis and neural correlates including the dopamine hypothesis.
Genetic basis - family studies
Family studies find individuals who have SZ and determine whether their biological relatives are similarly affected more often than non-biological relatives. Family studies have shown that the closer the genetic relatedness, the greater the risk. Gottesman (1991) found that if both parents were schizophrenic, then the likelihood of the offspring also having SZ was 46%, if one parent was schizophrenic, then the likelihood dropped to 13% and if a sibling (brother or sister) had SZ, the likelihood was 9% - this study shows that the more closer you are genetically related the more likely you are to get SZ.
Genetic basis twin studies
Twin Studies are an opportunity for researchers to investigate the nature/nurture debate in terms of the contribution of heredity and environmental influences in having SZ.
As Monozygotic twins (MZ) (identical twins) share 100% of their genes whereas as Dizygotic twins (DZ) (non-identical) twins share 50% of their genes, if SZ is genetic, then the concordance rates should be much higher for MZ rather than DZ twins!
Gottesman (1991) found a 48% concordance rate for MZ twins and 17% concordance rate for DZ twins- this study shows that the more genetically similar you are then the more likely you are to get SZ.
Furthermore in a more recent study, Joseph (2004) did a review of twin studies that were carried out up to 2001, and found an overall concordance rate for MZ twins as 40% but DZ twins as 7.4%. As the concordance rate is still relatively high for the MZ twins, his study supports the idea of genes playing a big part in SZ
Genetic basis - adoption studies
Adoption Studies - because it is difficult to separate genetic from environmental influences in twin and family studies, adoption studies are often carried out to understand the influence of nature and nurture. For example, adoption studies are researched to see the nature/nurture influences when MZ twins may be reared apart or offspring of SZ parents are adopted. Tienari et al (2001) carried out a study in Finland. 164 adoptees whose biological mothers had been diagnosed with SZ, 11 (6.7%) were also diagnosed with SZ compared to a control group of 197 adoptees where only 4 (2%) were diagnosed with SZ. This study shows that although the overall percentage of children (who have been adopted by non- schizophrenic parents) having SZ was very low, as there was a small link between genes and SZ with children whose biological mothers were schizophrenic.
Genetic basis - candidate genes
There are specific candidate genes that seemed to be associated with SZ (such the the PCM1) although it is now agreed that SZ is polygenic – this means that there is a combination of different genes that have been implicated in SZ.
Gurling et al (2006) used evidence from family studies indicating that SZ was associated with chromosome 8p21-22 to identify a high-risk sample. Using gene mapping, the PCM1 gene was implicated in susceptibility to SZ, providing more evidence for genetics. Also Benzel et al. (2007) used gene mapping to find evidence suggesting that NRG3 gene variants interact with both NRG1 and ERBB4 gene variants to create susceptibility to developing SZ, suggesting an interaction of genetic factors.
Ripke et al (2014) compared the genetic makeup of 37000 SZ patients worldwide with 113000 controls. They found that 108 separate genetic variations were associated with an increased risk of SZ. The genes that were particularly vulnerable were the ones that had some connection to the functioning of certain neurotransmitters such as dopamine.
Evaluation of genetic basis of SZ (1p,3n)
+ There is a wealth of research evidence to support the genetic basis for SZ as can be seen from the findings of Gottesman, Joseph’s and Tienari’s study, thus there is a link between genes and SZ.
- the problem with twin and family studies is separating nature (genes) from nurture (the environment). For example, MZ twins are normally reared together and sent to the same school, where the same clothes (in childhood), this then makes it difficult to separate upbringing from genes. Even if we look at adoption studies that attempt to separate genes from the environment, children tend to be adopted by relatives who may still rear the child similarly to its biological parents – thus adoption studies may not always be a good comparison for the effects of nature and nurture.
- SZ can take place in the absence of a family history. One explanation is that there may be a mutation in parental DNA, for example in paternal sperm cells. This can be caused by radiation, poison or infection. Evidence for role of mutation comes from Brown et al’s. (2002) study which showed a positive correlation between paternal age and increased risk of SZ increasing from around 0.7% with fathers under 25 to over 2% in fathers over 50. This suggests that although no direct genes are involved, a person can still get SZ if their father was older at the time of fertilisation. Shows how nature and nurture may both play a part rather than just genes
- Genetic explanation of SZ is also biologically reductionist as it is stating that one cause of SZ is simply your genes. In other words it is insinuating that if you possess the PCM1 gene then you will have SZ. This means that this explanation is ignoring other factors such as psychological factors and family upbringing which could be more important in explaining SZ – for example it has been found that certain parenting styles (e.g. the schizophrenogenic mother) in an individuals childhood could trigger symptoms of SZ in adulthood.