Psychotic Disorders

 

Psychosis is the misrepresentation of thoughts and perceptions that originate from a patient’s own mind which are experienced as reality. It is a symptom, not a diagnosis in itself and affects about 3% of the population.

 

Causes: With most psychiatric conditions, the aetiology of psychosis is seen with a biopsychosocial model:

Biological:

Genetics –> Twin studies have shown schizophrenia has 50% concordance rate in MZ  twins

Dopamine–> Antipsychotics block D2 receptors whereas L-Dopa induces psychosis

Neurodevelopmental –> Higher in people with low birth weight, developmental delay etc.

 

Psychological:

Prodrome –> Often preceded by patients exhibiting anxiety, depression and ideas of reference

– These people can be offered CBT to reduce risk of progression to full psychosis

 

Social:

Stress –> Linked to social deprivation, urbanisation and stressful live events

Schizophrenia

This is the most famous psychotic condition which was originally called “Dementia Praecox” by Kraepelin.

– It is more frequent in men typically arising before the age of 40 and is linked with the risk factors above

 

In a nutshell, the main problems of schizophrenia for patients (symptoms and side effects) can be conceptualised by looking at the dopamine pathways in the brain. There are 4 main dopaminergic pathways in the brain:

Mesolimbic (VTA to NAc) –> This is involved in the reward pathway and attributing salience to a stimulus

– Excessive dopamine activity here is thought to give positive symptoms: delusions, hallucinations etc.

 

Mesocortical (Pre-frontal cortex) –> Dopamine here is important for executive functioning, emotion, speech

– Underactive dopamine here is thought to give negative symptoms: alogia, anhedonia, blunted affect

 

Nigrostriatal (SNr to Basal Ganglia) –> Dopamine here increases voluntary motor movements

– Therefore, explains why anti-psychotics (D2-blockers) lead to extrapyramidal symptoms

 

Tuberoinfundibular (to anterior pituitary) –> Dopamine here is responsible for reducing prolactin output

– Explains why anti-psychotics (D2-blockers) elevate prolactin release giving hyperprolactinaemia

 

Symptoms: These can mostly be divided into positive and negative symptoms

a) Positive – This is defined as symptom that is present through its presence

  • Hallucinations – This is a perception which the patient experiences as coming from the outside world

– However, it occurs in the absence of an external stimulus

– The most common are 3rd person auditory hallucinations or voices giving running commentary

Charles-Bonnet Hallucination

This is a visual hallucinations in a person with partial or severe blindness

It is thought that visual impairment promotes sensory deafferentation, leading to disinhibition, thus resulting in sudden neural firings of the visual cortical regions

  • Delusions – A false belief out of keeping with the patient’s sociocultural background

– This is held with unshakeable conviction even in the face of contradictory evidence

– Most common is persecutory –> the belief that people are conspiring against you

– Delusions of reference –> the belief that people on TV/radio are talking to/about you

Specific Delusions
  • Cotard Syndrome – This a delusion which is characterised by a false belief of death

The patient believes that they are dead, or a part of their body is non-existent

– It is associated with psychotic depression and can lead to extreme neglect as patients believe they no longer need to eat or drink

 

  • De Clerambault’s syndrome – Called erotomania, it is a delusion about love

Seen in young woman, she will falsely believe that a famous person has fallen in love with her

 

  • Othello Delusion – The patient believes that their spouse is being unfaithful without any real proof

 

  • Folie à deux – When symptoms of a delusional belief, transmitted from one individual to another
  • Thought Disorder – an impaired capacity to sustain coherent discourse, in written or spoken language

 

  • Catatonia – These are abnormal movements experienced by some patients:

– Waxy flexibility (you can move a patient into a position and they will remain frozen there)

– Catatonic stupor (this is where a patient suddenly stops and stays there)

 

  • Passivity Phenomena – This is the belief that your thoughts/actions are no longer your own

– Includes thought insertion (something putting a thought into your head), thought broadcasting (everyone can read your thoughts) and thought withdrawal.

b) Negative – This is defined as symptom that is present through its absence. Remember by 5A’s:

Affect blunted = restricted emotion with poor emotional display

Alogia = paucity of speech

Asociality = social isolation

Anhedonia = Lack of pleasure

Avolition = Lack of motivation

Diagnosis: The DSM-5 needs >2 of the following experienced for 1 months. At least 1 should include 1-3:

  1. Delusions
  2. Hallucinations
  3. Disorganised speech
  4. Disorganised or catatonic behaviour
  5. Negative symptoms

Subtypes: These are recognised by the ICD-10.

Paranoid – This is the most common type of schizophrenia

– Prominent hallucinations and delusions but mostly normal intellectual functioning and emotion

– Person feels very suspicious and persecuted

 

Catatonic – uncommon type which is characterised by prominent psychomotor disturbances

– Patient display rigidity, posturing, and abnormalities of voluntary movement

 

Hebephrenic/Disorganised – This has early onset, with unpredictable behaviour and speech

– Affect and mood is inappropriate with giggling, mannerisms and pranks

– Patients can also have fleeting hallucinations and delusions

 

Residual – A long-term subtype where most symptoms have gone but the negative symptoms remain

 

Undifferentiated – cannot be classified into any of the other subtypes 

Management – The primary management will be oral antipsychotics in a staged approach

i) Antipsychotics –> 1st line is oral atypical anti-psychotics (quetiapine, olanzapine, risperidone)­­­

–> 2nd line is oral typical anti-psychotics (haloperidol, chlorpromazine etc.)

–> 3rd line is clozapine, only used for psychosis refractory to other treatments

 

When prescribing antipsychotics, must regularly monitor weight, lipids and glucose and ECGs:

– Always start at the minimum dose with monotherapy and then titrate up the medication

– Minimum length of treatment is 6 months

– For single episode (medicate for 6-24 months)    

– 2nd is 5 years medications     

– 3rd is life-long medication

 

ii) Psychotherapy –> CBT is offered to all patients, helps to challenge delusions and develop coping strategies

 

iii) Social support –> Need social support for appropriate housing, financial advice 

Delusional Disorder

This is a rare mental illness in which a patient experiences delusion, but with no accompanying hallucinations, thought disorder, mood disorder or flattening of affect.

 

Diagnosis:

Patient must show delusions in absence of any other psychotic symptoms or reversible cause (drugs)

 

Management:

Psychotherapy (CBT) is main line + Antipsychotics

Check out my free OSCE revision guidebook

Download here!