Clinical Characteristics of Schizophrenia including reliability and validity.

Clinical Characteristics of Schizophrenia including reliability and validity.

1. AO1

   • Brief facts and figures
     • 50 times higher risk of attempting suicide
     • Suicide is number one cause of premature deaths among people with schizophrenia
     • Over a lifetime, about 1% of the population will develop schizophrenia
   • DSM-V
     • Diagnostic and statistical manual of mental disorders 5th edition
     • Certain groups of symptoms can be classed together as a syndrome
     • Allows mental disorders to be diagnosed and treated
   • Selective criteria from DSM-V
     • Must have two or more characteristic symptoms present for a significant portion of time
       • e.g. delusions, hallucinations, disorganised speech
     • Social/occupational dysfunction for a significant portion of time
     • Duration: continuos signs of disturbance for at least 6 months
   • Positive and negative symptoms
     • Positive Symptoms are those that appear to reflect an excess or distortion of normal functions
       • e.g. delusions, hallucinations, disrorganied speech
     • Negative Symptoms are those that appear to reflect a loss of normal functions
       • e.g. effective flattening, alogia, avolition

2. AO2

   • DSM-V
     • Advantage of the DSM-V is that therapies are usually specific to certain disorders so a reliable diagnosis can point to a particular type of therapy
     • Disadvantage of the DSM-V is misdiagnosis as if this occurs, it could lead to inappropriate treatment and sometimes, wrongful institutionalisation
   • Reliability
     • Refers to the consistency of a measuring instrument to asses and diagnosis schizophrenia
       • Inter-rater reliability refers to whether two independent assessors give similar diagnoses
         • Challenges- WHALEY (2001)- found inter-rater reliability correlations in the diagnosis of Schizophrenia as low as +0.11
         • Supports- Jakobsen et al. (2005) took a random sample of 100 danish patients with a history of psychosis and found high sensitivity of inter rater reliability of 93%
           • AO3- Cultural Bias
       • Test-retest reliability refers to whether tests used to deliver these diagnoses are consistent over time
         • Supports- PRESCOTT et al. (1986) analysed the test retest reliability of several measure of attention and information processing in 14 chronic schizophrenics and found performances on these measures were stable over 6 months
           • AO3- Longitudinal
   • Validity
     • Refers to the extent that a diagnosis represents something that is real and distinct from other disorders and that the extent the DSM-V measures what it claims to measure
       • Comorbidity refers to the extent that two or more conditions co-occur. Psychiatric comorbidities are common in schizophrenics including substance abuse, anxiety and symptoms of depression
         • Support- BUCKLEY et al. (2009) estimate that comorbid depression occurs in 50% of patients and 47% of patients also have a lifetime diagnosis of comorbid substance abuse. This creates difficulties in the diagnosis of the disorder as well as treatment.
     • ROSENHANN- being sane in insane places
       • AO3- ethics