classification and diagnosis

• Schizophrenia is a severe long-term mental health disorder which causes a range of different psychological symptoms.
• There are two main systems in which to classify schizophrenia: the International Classification of Disease (ICD) and the Diagnostic and Statistical Manual edition 5 (DSM-5).
• The DSM is widely used in America.

  The ICD is more common in Europe.
• Positive symptoms: experiences that are in addition to normal experiences such as hallucinations or delusions
• Hallucinations - additional sensory experiences such as seeing distortions in objects that look like faces/hearing critical voices.
• Delusions - irrational beliefs about themselves or the world.
• Negative symptoms: loss of normal experiences and abilities such as avolition and speech poverty
• Avolition - a lack of purposeful, willed behaviour. No energy, sociability, affection or attempt at personal hygiene. Generally apathetic.
• Speech poverty - Loss of quality and quantity of verbal responses. It can be classified as a positive symptom if speech is excessively disorganised, with sufferers wandering off the point.
• The DSM requires at least one positive symptom to diagnose schizophrenia.
• the ICD only requires two negative symptoms to diagnose schizophrenia.
• The differences between these classification systems means there are problems with reliability.
• In terms of diagnosis, inter-reliability means the extent to which two or more mental health professionals arrive at the same diagnosis for the same individuals.
• Cheniaux et al (2009) had two psychiatrists independently diagnose 100 patients using DSM and ICD. Inter-rater reliability was poor - one using the DSM diagnosed 26 and using ICD diagnosed 44 with schizophrenia whereas the other diagnosed 13 using DSM and 24 using ICD.
• there is overlap between symptoms of schizophrenia and other disorders. Under the ICD, a person may be diagnosed with schizophrenia but under DSM be diagnosed with bipolar disorder. This questions the validity.
• Co-morbidity is the presence of two or more disorders at the same time.
• Buckley et al (2009) concluded that half of patients with schizophrenia were also diagnosed with depression or substance abuse.
• There are problems with reliability in terms of gender-bias in diagnosis, most likely based on gender stereotypes.
• Longnecker et al (2010) reviewed studies on the prevalence of schizophrenia and concluded that since the 1980s, men have been diagnosed with schizophrenia more often than women.
• Female patients typically function better than men, being more likely to work and have good family relationships (Cotton et al 2009). This may bias practitioners to under-diagnose schizophrenia.
• Loring and Powell randomly selected psychiatrists to read cases of patient behaviour. 56% of psychiatrists diagnosed schizophrenia when the patient was male or unspecified. 20% diagnosed schizophrenia when the patient was female. This bias was less common in female psychiatrists.
• There is gender and cultural bias in diagnosis of schizophrenia. A case study found over-diagnosis of black clients and under-diagnosis of female clients.
• One of the main symptoms, hearing voices, is affected by the cultural environment. It is more acceptable in African cultures due to their belief in communication with ancestors, which psychiatrists in other cultures may view as irrational