Diagnosing Schizophrenia

• Classification of mental disorders is the process of organising symptoms into categories based on which symptoms frequently occur together
• Schizophrenia is a severe mental disorder where contact with reality and insight are impaired
• Positive symptoms are additional experiences
• Negative symptoms are a loss of usual experiences
• Positive symptoms of schizophrenia include hallucinations and delusions
• Hallucinations are sensory experiences which either have no base in reality or are distorted perceptions of reality
• Negative symptoms of schizophrenia include speech poverty and avolition
• Delusions (AKA paranoia) are irrational beliefs that have no basis in reality
• Speech Poverty is the reduced frequency and quality of speech and delayed verbal responses
• Avolition (AKA apathy) is the loss of motivation to carry out tasks
• Nancy Andreasen defines Avolition as poor hygeine, lack of persistence in work/education, lack of energy
• The diagnosis of schizophrenia is high in reliability, as shown by Flavia Osorio et.al.
• Flavia Osorio at.al. reported inter-rater reliability of 0.97 and test-retest reliability of 0.92 in diagnosing schizophrenia
• Diagnosing schizophrenia is low in validity as it is suggested that it is either under- or over-diagnosed
• Co-morbidity is the occurence of two or more conditions together
• Co-morbidity lowers the validity of diagnosing schizophrenia
• Symptom overlap is common e.g. BPD so lowers the accuracy of diagnosing schizophrenia
• Gender bias lowers the validity of schizophrenia diagnoses as more men are diagnosed (ratio of 1:4:1)
• Gender bias may occur because women have closer relationships so may gain more support
• Culture bias lowers the validity of schizophrenia diagnoses e.g. Afro-Carribean societies may attribute voices to communication with ancestors