Symptoms of Schizophrenia

What is Schizophrenia?

Schizophrenia is a mental disorder characterised by psychosis, where individuals struggle to distinguish between reality and their own thoughts.

Positive Symptoms

Positive symptoms are an excess or distortion of normal functioning and are additional experiences beyond typical behaviour.

Hallucinations are distorted sensory experiences that can involve any of the senses, although auditory hallucinations, such as hearing voices, are the most common.

Delusions are irrational and false beliefs. These often involve paranoia, such as believing one is being controlled or persecuted, or grandiose beliefs, such as believing one is a powerful or important figure.

Negative Symptoms

Negative symptoms involve a loss or reduction of normal functioning.

Speech poverty refers to a reduction in the amount and quality of speech, making communication limited and less meaningful.

Avolition refers to a lack of motivation and difficulty initiating or sustaining goal-directed behaviour, often resulting in poor hygiene, reduced effort in work or education, and low energy levels.

Issues in Diagnosis

Key Issues

Co-morbidity refers to the presence of two or more disorders at the same time. Schizophrenia is often diagnosed alongside other conditions, with around 50 percent of patients also experiencing depression, 47 percent substance abuse, and 23 percent obsessive compulsive disorder, as reported by Buckley et al. (2009). This makes diagnosis difficult and raises questions about whether schizophrenia is a distinct disorder.

Culture bias occurs when diagnostic systems do not account for cultural differences. For example, African-Caribbean individuals in the UK are significantly more likely to be diagnosed with schizophrenia than White British individuals, suggesting possible bias in diagnosis.

Gender bias is seen in higher rates of diagnosis in men than women. However, Cotton et al. (2009) suggested that women may function better due to stronger social support, leading to underdiagnosis.

Symptom overlap occurs because symptoms of schizophrenia, such as hallucinations and mood changes, are also found in other disorders such as bipolar disorder. This makes it difficult to distinguish between conditions.

Evaluation of Issues in Diagnosis

Co-morbidity reduces the validity of diagnosis because overlapping conditions make it unclear whether schizophrenia is a separate disorder. Buckley et al. (2009) demonstrated high rates of co-occurring conditions, supporting this issue.

Cultural bias may lead to overdiagnosis or misdiagnosis in certain groups. The higher rates in African-Caribbean populations suggest that clinicians may interpret culturally specific behaviours as symptoms.

Gender bias may result in underdiagnosis of women, meaning they may not receive appropriate treatment. Cotton et al. (2009) supported this by showing differences in functioning between men and women.

Symptom overlap reduces reliability, as clinicians may disagree on diagnoses when symptoms are shared across disorders.

Biological Explanations

Genetic Explanations

Family studies show that the likelihood of developing schizophrenia increases with genetic similarity. Gottesman (1991) found concordance rates of 48 percent for identical twins, 17 percent for fraternal twins, and 6 percent for parents, compared to around 1 percent in the general population.

Schizophrenia is considered polygenic, meaning it is influenced by multiple genes, particularly those involved in dopamine functioning.

Mutation may also play a role, as genes can be altered by environmental factors such as infection or radiation, even without a family history.

Evaluation of Genetic Explanations

The fact that concordance rates for identical twins are not 100 percent suggests that environmental factors must also play a role. Morkved et al. (2017) found that many patients had experienced childhood trauma.

Differences in diagnostic criteria reduce reliability across studies. Cardno et al. (1999) found lower concordance rates when stricter diagnostic criteria were used.

Adoption studies support a genetic basis. Hiker et al. (2018) found that concordance rates remained higher for identical twins even when raised apart.

There are applications such as genetic counselling, which can estimate the risk of developing schizophrenia. However, this only provides probabilities and does not account fully for environmental influences.

Neural Correlates and Dopamine Hypothesis

The dopamine hypothesis suggests that schizophrenia is linked to abnormal levels of dopamine in the brain.

Hyperdopaminergia refers to excessive dopamine activity in subcortical areas, which is associated with positive symptoms such as hallucinations.

Hypodopaminergia refers to low dopamine activity in the prefrontal cortex, which is associated with negative symptoms such as reduced thinking ability.

Research has also identified reduced activity in brain areas such as the ventral striatum, which is linked to reward anticipation, and the superior temporal gyrus, which is associated with auditory hallucinations.

Evaluation of Neural Correlates and the Dopamine Hypothesis

Support for the dopamine hypothesis comes from drug treatments. Antipsychotic drugs reduce dopamine levels and alleviate symptoms, while drugs that increase dopamine, such as amphetamines, can worsen symptoms.

However, other neurotransmitters may also be involved. McCutcheon et al. (2020) highlighted the role of glutamate in schizophrenia, suggesting the dopamine hypothesis may be incomplete.

A limitation is that neural correlates are correlational. Differences in brain activity do not necessarily cause schizophrenia and may instead be a result of the disorder.

Psychological Explanations

Family Dysfunction

The schizophrenogenic mother theory, proposed by Fromm-Reichmann (1948), suggests that a cold, rejecting, and controlling mother creates an environment that leads to paranoid delusions in the child.

The double bind theory suggests that children exposed to contradictory communication from parents experience confusion, which may contribute to disorganised thinking and paranoia.

Expressed emotion refers to high levels of criticism, hostility, and emotional overinvolvement within a family, which can increase relapse rates.

Evaluation of Family Dysfunction

There is support linking family environment to schizophrenia. Read et al. (2005) found high rates of childhood abuse in patients with schizophrenia, suggesting family dysfunction may contribute to vulnerability.

These explanations raise ethical issues, as they blame parents for causing the disorder, making them socially sensitive.

Some support exists for the double bind theory. Berger (1965) found that individuals with schizophrenia recalled more contradictory communication.

However, there is limited scientific evidence, and many claims are based on retrospective accounts rather than controlled studies.

Cognitive Explanations

Cognitive explanations focus on dysfunctional thinking processes.

Metarepresentation dysfunction refers to an inability to recognise that thoughts and actions are self-generated, which can lead to hallucinations and delusions.

Central control dysfunction refers to an inability to suppress automatic thoughts, leading to symptoms such as speech poverty.

Evaluation of Cognitive Explanations

There is support from brain imaging studies. PET scans show reduced activity in areas involved in self-monitoring, such as the frontal lobe.

Stirling et al. (2006) found that individuals with schizophrenia performed poorly on cognitive tasks such as the Stroop test, suggesting impaired processing.

Cognitive explanations are considered proximal explanations because they explain current symptoms rather than the original cause of schizophrenia.

They may be best explained through the diathesis-stress model, as biological factors may underlie cognitive impairments.

Drug Therapy

Typical and Atypical Antipsychotics

Typical antipsychotics work as dopamine antagonists by blocking dopamine receptors. This initially increases dopamine but reduces production over time, decreasing positive symptoms. They also have a calming, sedative effect.

Atypical antipsychotics act on both dopamine and serotonin systems and are effective for both positive and negative symptoms. They generally have fewer side effects.

Interactionist Approach

Diathesis-Stress Model

Meehl (1962) proposed that a single gene created vulnerability, but modern understanding suggests multiple genes and environmental factors, such as trauma or drug use, contribute.