Schizophrenia

Schizophrenia

Sarah Brown-Short                                                                                               

Classification of Schizophrenia

Schizophrenia(Sz) is a psychotic disorder which is characterized by a loss of contact with reality. It occurs in only 1% of the population, affecting males and females equally, but usually appears later in females.To give a diagnosis, the DSM-V or ICD-10 is used. 

Rule of quarters:

·         25% recover fully

·         25% improve but have slight symptoms recurring 

·         25% improve slightly but relapse

·         25% show no improvement, 10% of which will die, usually by suicide

Schizophrenia has positive and negative symptoms. Positive symptoms are things that are in addition to normal functioning, while negative symptoms are a loss of normal functioning

Positive symptoms 

·         Delusions: These are bizarre beliefs which feel real to the sufferer but are not actually.

·         Disordered thinking: Feelings that thoughts have been inserted or withdrawn from a person’s mind. Individuals may also feel their thoughts are being broadcast to a group of people. Indicators of this are tangential, incoherent, loosely associates speech

·         Experiences of control: individuals will feel that they are under the control of an external force, such as the government or aliens, which has invaded mind and body

·         Hallucinations: Bizarre, unreal perceptions

Negative Symptoms

·         Affective Flattening: Range and intensity of emotional expression will be lost. This impacts facial expression, tone, and body language.

·         Alogia: Poverty of speech, loss of fluency and productivity to reflect slow or blocked thoughts

·         Anhedonia: loss of interest and pleasure, lack of reactivity to stimuli

·        

Evaluating negative symptoms

·         Often start before the positive symptoms (can be years- alternate diagnosis given first)

·         Less easily affected by cultural factors that positive symptoms

·         Easier to objectively measure than positive symptoms

Avolition: Loss or reduction in goal directed behaviour, mistaken for lack of interest and no motivation

·         Catatonia: immobility or unresponsiveness

Are diagnoses of Sz reliable?

Reliability refers to consistency. Inter-rater reliability refers to consistency between two or more clinicians diagnosing an individual with schizophrenia, and is measured by a “kappa score” of which 0.7 or higher is considered good enough. Test-retest refers to an individual being diagnosed with schizophrenia on two separate occasions.

Research to suggest that diagnoses are not reliable:

·         Regier et al(2013) found that using the DSM-5 there was only a kappa score of 0.46

·         Mojtabi&Nicholson(1995) found that when differentiating between bizarre and non-bizarre delusions, there was only a 0.4 inter-rater kappa score.

·         Whaley(2001) found that  there was only a kappa score of 0.11 when using the DSM