AO3

• A limitation is co-morbidity with other conditions. If conditions often co-occur then they might be a single condition. Schizophrenia is commonly diagnosed with other conditions, for example, Buckley et al. concluded that schizophrenia is comorbid with depression in 50% of cases, substance abuse in 47% of cases, or OCD in 23% of cases. This suggests that schizophrenia may not exist as a distinct condition.
• A strength of diagnosis of schizophrenia is that it has good reliability. A reliable diagnosis is consistent between clinicians and between occasions through inter-rater and test retest validity. Osorio et al report excellent reliability for the schizophrenia diagnosis. with the DSM-5 with an interrater agreement of + 0.97 and test retest ability of + 0.92. This means that the diagnosis of schizophrenia is consistently applied.
• A further limitation is gender bias. Men are diagnosed with schizophrenia more often than women in a ratio of 1.4:1. This could be because men are more genetically vulnerable or women have better social support and masking symptoms. This means that some women with schizophrenia are not diagnosed so miss out on helpful symptoms.
• A further limitation is culture bias. Some symptoms, like hearing voices, are accepted in some cultures, e.g. in some Afro-Caribbean societies people have claimed to hear voices from their ancestors. Afro-Caribbean British men are up to 10 times more likely to receive a diagnosis as British white men, probably due to over-interpretation of symptoms by psychiatrists. This means that Afro-Caribbean men living in the UK appear to be discriminated against by a culturally biased diagnostic system
• A limitation is symptom overlap. There is overlap between the symptoms of schizophrenia and other conditions. For example, both Schizophrenia and Bipolar Disorder involve delusions and avolition. Schizophrenia and Bipolar Disorder may be the same condition. Schizophrenia is a hard-to-distinguish from bipolar disorder. This means that schizophrenia may not exist as a condition, and if it does, it is hard to diagnose.