Psychotic Disorders Flashcards
What is schizophrenia?
Common chronic relapsing condition often presenting in early adulthood with psychotic symptoms (e.g. hallucinations, delusions); a psychotic disorder
- Disorganisation of symptoms (incongruous mood, abnormal speech and thought)
- Negative symptoms (apathy, reduced motivation, withdrawal, self neglect, blunted mood
- Prevalence: 1% (males = females)
- Clear consciousness and intellectual capacity are usually maintained
- Can be continuous or episodic
ICD-10 Schizophrenia?
1 or more:
a) Thought ECHO (hearing own thoughts aloud), WITHDRAWAL, BROADCASTING or INSERTION
b) Delusions of control, influence or passivity clearly referred to body or limb movements or specific thoughts, actions or sensations
c) Hallucinatory voices giving running commentary on patient, or two voices discussing the patient, or voices from other parts of the body
d) Persistent delusions of other kind that are culturally inappropriate and impossible
Or at least 2 of the following:
e) Persistent hallucinations in any modality when every day for at least 1 month, when accompanied by delusions, without clear affective content or when accompanied by persistent overvalued ideas
f) Neologisms, interpolation or breaks in the train of thought resulting in incoherent or irrelevant speech
g) Catatonic behaviour such as excitement, posturing or waxy flexibility, negativism, mutism and stupor
h) “negative symptoms” such as marked apathy, paucity of speech and blunting or incongruity of emotional responses (must be clear that this is not due to depression or neuroleptic medication)
ICD-10 EXCLUSION criteria for schizophrenia?
Patient meets criteria for manic or depressive episode (or the criteria above must be met before there is a disturbance to mood)
- Disorder not attributable to organic brain disease or to alcohol/drug related intoxication, dependence or withdrawal
What are the symptoms of schizophrenia?
first rank
Women (25+) experience symptoms later than men (18-30)
• Chronic, relapsing course
Schneider’s first rank symptoms:
- Delusional perception
- 3rd person auditory hallucinations
- Thought interference (insertion, withdrawal and broadcast)
- Passivity phenomenon – feeling like their mood/actions are being controlled by someone or something else
Note - first rank can occur in other disorders like mania or delirium so their presence alone not sufficient for diagnosis.
4 phases of schizophrenia?
Premorbid
o Lack of evidence to diagnose illness
o Not necessarily “non-pathological”; neurodevelopment changes may be occurring
Prodromal
o Adolescence
o Subtle and non-specific symptoms, e.g. low mood, irritability, social withdrawal
o Identifying schizophrenia at this stage is key for early intervention and better outcome
Active
o When the actual diagnosis is made
o Chaotic
o Can last many years; repeated psychotic episodes cause progressive deterioration in function
Residual
o Further psychotic episodes to cause a further decline in function
Types of schizophrenia?
Paranoid (most common)
- Sudden onset
- Prominent hallucinations and delusions; dominated by positive symptoms (thought disorder, disorganised behaviour, affective flattening not present)
Simple (insidious and progressive negative symptoms)
- Deterioration in personality
- Blunted affect
- Emotional and social withdrawal
- Inability to meet the demands of society
- No history of psychotic episodes
Hebephrenic
- Adolescent onset
- Disturbances in thinking, perception, affect and behaviour
- Inappropriate mood often coupled with giggling, self-absorbed smiling and grimacing
- Disorganised symptoms
Catatonic
- Rare! – stopping of voluntary movement or staying still in an unusual position
- Disturbances of movement (including increased muscle tone) and behaviour
- Can be hyperkinetic or stupor (near unconsciousness) or automatic obedience and negativism
Residual Type
- positive symptoms at lower intensity
What are positive symptoms of schizophrenia?
Typically in acute phases of illness; excess of normal functions
Hallucinations
Delusions
Inappropriate affect
Abnormalities of thought
Agitation/excitement
What are negative symptoms of schizophrenia?
Social withdrawal Apathy Blunted affect Thought blocking Poverty of speech > self neglect, disengagement from social neglect
What are disorganised symptoms of schizophrenia?
Disorganized thinking/speech
Disorganised behaviour
Inappropriate affect
Circadian rhythm disturbance – e.g. insomnia
What are Schneider’s First Rank Symptoms?
- Auditory hallucinations – third person, running commentary
- Delusions of thought control – thought insertion, withdrawal, broadcasting
- Delusions of control – passivity of affect, volition and impulses; somatic passivity (patient’s sensations are controlled by an external body)
- Delusional perceptions
Aetiology of schizophrenia?
Genetic
• Lifetime risk in 1st degree relatives is 15% (10 times the risk of general population)
• Risk in monozygotic twins ~46% and ~10% in dizygotic
• Polygenic transmission of vulnerable characteristics – i.e. a predisposition to schizophrenia is inherited rather than the condition itself
• 2 hit hypothesis: 1st hit – genetic vulnerability; 2nd hit – environment
• Onset of schizophrenia in two siblings occurs when at the same age, rather than when they have both been exposed to a shared experience
Neurodevelopment
• Neurodevelopment disruption in utero
• Structural differences seen (at both onset and later stages of illness): ventricular enlargement, temporal lobe reduction
• Obstetric complications (e.g. perinatal hypoxia, viral infection) can affect fetal neurodevelopment > development of schizophrenia later in life
• People born in the winter are 10% more likely to develop the illness (suggesting environmental factors such as temperature and viral infection has an affect)
• Study in 1994: children with schizophrenia went on to develop neurobehavioural + neuromotor abnormalities (e.g. delayed psychomotor milestones, speech problems, poorer educational test scores, social isolation, greater anxiety)
• Unique individual experiences will interact with neuropathology to produce the vast variety of clinical presentations
Neurochemistry
• Altered neurochemical function, perhaps due to altered gene expression or brain development
• LSD was the first drug to suggest an association between neurotransmitter disturbance and psychosis
• Excess dopamine (in mesolimbic pathway) positive symptoms of schizophrenia (e.g. delusions, hallucinations)
• Too little dopamine (in mesocortical pathway) negative symptoms (e.g. social and emotional withdrawal)
• Stress vulnerability hypothesis: stressful events relapse of condition
• Studies have found that NMDA antagonists (i.e. PCP), ketamine and 5HT agonist (LSD) can induce schizophrenia like psychosis
Stress-vulnerability model
• Genetic variations make an individual more or less vulnerable to developing schizophrenia
• A person who is highly vulnerable but has barely any stressors in their life will be at a lower risk than someone who is moderately vulnerable but has many stressors
Environmental factors
• Cannabis and other drugs: people who smoke cannabis are up to 6 times more likely to develop schizophrenia (other stimulants such as amphetamines, cocaine and ecstasy are also linked)
• Incidence tends to be greater in immigrants
Poor prognostic factors for schizophrenia?
- Strong FH
- Gradual onset
- Low IQ
- Premorbid history of social withdrawal
- Lack of obvious precipitant
Other differentials for schizophrenia?
Psychiatric differentials • Drug induced psychosis • Bipolar disorder • Schizoaffective disorder • Depressive or manic psychosis • Puerperal psychosis • Personality disorder
Organic differentials • Delirium, dementia • Stroke • Temporal lobe epilepsy • CNS infections – e.g. AIDS, neurosyphilis • Head trauma, brain tumour • Endocrine – e.g. Cushing’s syndrome • SLE
Other differentials for schizophrenia?
Psychiatric differentials • Drug induced psychosis • Bipolar disorder • Schizoaffective disorder • Depressive or manic psychosis • Puerperal psychosis • Personality disorder
Organic differentials • Delirium, dementia • Stroke • Temporal lobe epilepsy • CNS infections – e.g. AIDS, neurosyphilis • Head trauma, brain tumour • Endocrine – e.g. Cushing’s syndrome • SLE
Outline dopamine pathways in brain?
Excess in mesolimbic system causes positive symptoms
Too little in mesocortical system causes negative symptoms
Nigrostriatal - dopamine suppresses cholinergic activity and serotonin inhibits dopamine release
