Psychotic Disorders Flashcards
Define psychosis
Presence of hallucinations or delusions
What is a hallucination?
Perception without a stimulus
Can be in any sensory modality
Visual hallucination = normally prob with the brain or eyes
In the ‘normal’ population what types of hallucinations are experienced?
Hypnogogic = going to sleep
Hypnopompic = waking up
What is a delusion?
Abnormal belief, outside of culturing norms, unshakeable
What are the causes of organic psychosis?
Delirium causes by infection
Acute drug/alcohol intoxication
Hyperthyroidism
Encephalitis
Hypercalcaemia
Iatrogenic = steroids, L-dopa
List the first rank symptoms
Auditory hallucinations = thought echo, running commentary
Passivity experiences = believes action/feeling is caused by external force
Thought withdrawal, broadcast or insertion
Delusional perceptions = attribution of new meaning
Somatic hallucination = mimics feelings from inside the body
What are the types of schizophrenia?
Paranoid schizophrenia = delusions, hallucinations
Simple schizophrenia = easily mistaken for depression, marked decline in social/academic/social performance
Hebephrenic schizophrenia = childlike
Undifferentiated schizophrenia
Catatonic schizophrenia
Outline the pathophysiology of schizophrenia
Dopamine pathways – hyperactive signal transduction
Brain changes = enlarged ventricles, reduced hippocampal formation, amygdala, parahippocampal gyrus and prefrontal cortex
Limbic system = brocas area can produce illogical language
What is the mesolimbic pathway
From ventral tegmental area to limbic structures
Motivation, pleasure
Overactive in schizophrenia
What is the mesocortical pathway
From ventral tegmental area to frontal cortex and cingulate cortex
Cognition, motivation, cognition response
Underactive in schizophrenia
How is schizophrenia treated?
Typical antipsychotics = block D2 receptors, in all dopaminergic pathways (block all = SIDE EFFECTS)
Atypical antipsychotics = low affinity for D2, milder side effects as dissociate rapidly from D2 receptor
What is haloperidole?
Antipsychotic medication
Oral, IM, IV
D2 dopamine receptor antagonist
What are the ADRs from using antipsychotic?
Acute dystonia = head stuck to one side, cant talk or swallow (procyclineve, anticholinergic)
Parkinson’s symptoms = shuffling gait
Outline a nigrostriatal pathway
From substantia nigra to striatum
Less dopamine = less movement
What drugs can induce psychosis?
Methamphetamine, cannabis, cocaine, amphetamines, LSD, ecstasy, ketamine
During or within 2 weeks of substance use
