Psychosis and Schizophrenia Flashcards
What is schizophrenia?
A psychotic syndrome characterised by a cluster of heterogeneous symptoms causing clear and marked deterioration in the patient’s functioning and socialising
What is psychosis and psychotic symptoms?
-Psychosis: experience of reality is grossly distorted.
-Psychotic symptoms comprise delusions, hallucinations and thought disorder.
=A delusion is a fixed, false, belief which arises through faulty reasoning, is not altered by evidence to the contrary and is outside cultural norms.
=A hallucination is a perception in the absence of a stimulus.
=Thought disorder is speech so disorganized that communication is impaired.
Features of schizophrenia
-Positive symptoms
=Delusions are fixed beliefs, arrived at illogically, not amenable to reason ,and not accepted in the patient’s cultural background: persecutory, thought interference, passivity delusions
=Hallucinations are perceptions which occur in the absence of an external stimuli: third person auditory
=Thought disorder is speech so disorganized that communication is impaired: formal thought disorder, neologisms
-Negative symptoms
=Apathy, poverty of thought/speech (alogia), blunted affect, flattening mood, anhedonia, social isolation, poor self-care, impairment or loss of volition, motivation (avolition), spontaneous behaviour. Loss of awareness of socially appropriate behaviour. Catatonia.
- Perception (process of making sense of the physical information we receive from our sensory modalities)
- Abnormal beliefs
- Thought disorder
- Negative symptoms
- Psychomotor function
Describe hallucination characteristics
-To the patient, the nature of a hallucination is the same as a normal sensory experience (i.e. it appears real). Therefore patients often have little insight into their abnormal experience.
-They are experienced as external sensations from any one of the sensory modalities (e.g. hearing, vision, smell, taste, touch) and should be distinguished from ideas, thoughts, images or fantasies which originate in the patient’s own mind.
-They occur without an external stimulus and are not merely distortions of an existing physical stimulus
=Auditory: elementary (whirring/buzzing)/ complex (1st/2nd/3rd person)
=Visual
=Somatic: kinaesthetic (joint or muscle sense), visceral (organs), superficial (tactile/ haptic: touch, thermal, hygric: fluid)
=Olfactory
=Gustatory (taste)
=Special: extracampine (outside limit of normal sensory field), functional (normal sensory stimulus required to precipitate hallucination), reflex, hypnopompic (waking)/ hypnagogic (sleeping)
-Illusions: misperceptions of real external stimuli
-Pseudohallucination: hallucinations that patients recognize as false perceptions
Describe delusions
-To the patient, there is no difference between a delusional belief and a true belief; they are the same experience. Therefore only an external observer can diagnose a delusion. A delusion is to ideation what an hallucination is to perception: both have the quality of reality to the person experiencing them.
-The delusion is false because of faulty reasoning. A man’s delusional belief that his wife is having an affair may actually be true (she may indeed be unfaithful), but it remains a delusion because the reason he gives for this belief is undoubtedly false (e.g. she ‘must’ be having an affair because she is part of a top-secret sexual conspiracy to prove that he is a homosexual).
-A delusion is out of keeping with the patient’s social and cultural background. It is crucial to establish that the belief is not one likely to be held by that person’s subcultural group (e.g. a belief in the imminent second coming of Christ may be appropriate for a member of a religious group, but not for a formerly atheist, middle-aged businessman).
-Classification
=Primary or secondary
=Mood congruent or mood incongruent
=Bizarre or non-bizarre
=According to the content of the delusion
What is an overvalued idea?
-A plausible belief that a patient becomes preoccupied with to an unreasonable extent.
-The key feature is that the pursuit of this idea causes considerable distress to the patient or those living around them (i.e. it is overvalued).
-Patients who hold overvalued ideas have usually had them for many years and typically have abnormalities of personality.
-They are distinguished from delusions by the lack of a gross abnormality in reasoning; these patients can often give fairly logical reasons for their beliefs. They differ from obsessions in that they are not experienced as recurrent intrusive thoughts.
-However, one will frequently encounter beliefs that span definitions. Typical disorders that feature overvalued ideas are anorexia nervosa, hypochondriacal disorder, dysmorphophobia, paranoid personality disorder and morbid jealousy (this can also take the form of a delusion)
Examples of thought disorders
-Circumstantial/ over inclusive thinking: less relevant associations, goal is reached but by circuitous route
-Tangential thinking flight of ideas: less relevant associations, goal never reached, normal speed= tangential, accelerated speed= flight of ideas
-Loosening of associations: poorly or unrelated concepts, unclear goal
-Word salad: completely incomphrensible
Describe catatonic symptoms
-Rigidity: maintaining fixed position and rigidly resisting all attempts to be moved
-Posturing: adopting an unusual or bizarre position that is then maintained for some time
-Negativism: motiveless resistance to all instructions or attempts to be moved (opposite of what is asked)
-Waxy flexibility: moulded like wax into position that is then maintained
-Excitement: agitated, excited, seemingly purposeless motor activity not influenced by external stimuli
-Stupor: akinesis, mutism, extreme unresponsiveness
-Echopraxia: repeat or imitate actions around them
-Mannerisms: apparently goal-directed movements (waving, saluting) repeatedly or socially inappropriate
-Stereotypies: complex, identically repeated movement that does not appear to be goal-directed (rocking)
-Tics: involuntary, rapid, sudden recurrent, nonrhythmic motor movements or vocalisations
Describe Schneider’s first rank symptoms
- Auditory hallucinations
=Thought echo
=Discussion of patient/voices arguing/ 2+ voices discussing in third person
=Running commentary/ commenting on patient behaviour - Delusions of control/ passivity phenomena
=Passivity of mood/feelings
=Passivity of impulse
=Passivity of actions
=Bodily sensations under control of external force - Delusions of thought control
=Insertion
=Withdrawal
=Broadcast - Delusional perception
=a true perception of an external stimulus is interpreted in a delusional way i.e. a red sock seen hanging on laundry line means that aliens are coming to attack your house
Subtypes of schizophrenia
-Paranoid
=Dominated by hallucinations/ delusions
=Prognosis better and onset later (18-25 years)
=Negative and catatonic symptoms not prominent
-Hebephrenic (disorganised)
=Primarily thought and speech disorganisation (often silly/ shallow)
=Also disturbed behaviour and inappropriate/flat affect
=Prognosis poorer and onset earlier (15-25 years)
=Delusions and hallucinations fleeting
-Catatonic
=Rare, characterised by 1+ catatonic symptom
=Psychomotor disturbance
-Residual
=1 year of predominately chronic negative symptoms preceded by at least one clear-cut psychotic episode
-Post-schizophrenic depression
=Some residual symptoms, but depressive picture predominates
-Simple
=No delusions or hallucinations- a defect state (negative symptoms) gradually arises without acute episode
Epidemiology of schizophrenia
-Affects 1% of the world’s population
-Increased prevalence in lower socioeconomic classes
-Incidence M 1.4:1 F
=Equal prevalence possibly due to increased mortality in male sufferers
-Age of onset late teens to mid 30s (later in women)
-Strongest risk factor for developing a psychotic disorder= family history.
=Having a parent with schizophrenia leads to a relative risk RR of 7.5
-Other risk factors: back Caribbean ethnicity, migration, urban environment, cannabis use
Aetiology of schizophrenia
-Caused by multifactorial combination of genetics and environment
=Brain abnormalities
=Neurotransmitter abnormalities (dopamine DR receptors and glutamate)
-Risk factors:
=Positive family history: ~10% risk if a first degree family member is affected, 50% risk if both parents affected, or a monozygotic twin has the illness
=Cannabis-use (risk x2 for smoking on ten occasions; tipping point for the pre-disposed)
=PTSD or experience of adverse life events (increases risk 3-fold)
=Birth during winter/spring, maternal starvation (risk x2)
Differentia diagnosis: psychotic symptoms
-Schizophrenia
-Schizophrenia-like disorder
-Schizoaffective disorder
-Delusional disorder
-Depressive or manic episode with psychosis
-Psychosis secondary to a medical condition (Brain: head injury, CNS infection, tumour, TLE, post-epileptic states, vCJD/ metabolic: hypernatraemia, hypocalcaemia/ endocrine: hyperthyroidism, Cushing’s)
-Psychosis secondary to substance use (alcohol, stimulants, hallucinogens, steroids, antihistamines, sympathomimetics)
-Dementia
-Delirium
-Personality disorder
-Neurodevelopmental disorder (ASD)
Overview of schizophrenia-like psychotic disorders
-Abrupt onset (without a prodromal phase), precipitated by an acute life stress, or to have a shorter duration of symptoms than that usually observed in schizophrenia.
-The ICD-10 codes these as acute and transient psychotic disorders.
- Often these diagnoses are superseded by a later diagnosis of schizophrenia as the clinical picture evolves
Overview of schizoaffective disorder
-Presentation of both schizophrenic and mood (depressed or manic) symptoms that present in the same episode of illness, either simultaneously or within a few days of each other.
-The mood symptoms should meet the criteria for either a depressive or manic episode.
-Patients should also have at least one, preferably two, of the typical symptoms of schizophrenia (i.e. symptoms (a) to (d) as specified in the ICD-10 schizophrenia diagnostic guidelines
