Psychotic Disorders

psychotic disorders

• grouped together due to similarities in symptoms, not because they
  are thought to be etiological similar

• “Psychotic” can be difficult to define and includes a wide range of behaviours and inner experiences:

  • Delusions and/or hallucinations without insight

  • Hallucinations with insight

  • Disorganized speech or behaviour

  • Level of functional impairment is often important

• Positive symptoms – exaggerated or distorted versions of normal behaviour

  • Delusions, hallucinations, disorganized thoughts and speech, catatonic behaviour, polydipsia

• Negative symptoms – absence or lack of typical behaviour

  • Avolition, apathy, sparse speech, social withdrawl, cognitive problems

sub-threshold psychotic symptoms

• Common in people without diagnosable mental illness

• Magical thinking: Unlikely beliefs about relationships between events

• Paranoid thinking: Irrational beliefs or thoughts that other people are planning harm

• Unusual visual or other sensory experiences

• Ganzfeld effect: a way to induce harmless temporary visual hallucinations

psychotic disorders: positive symptoms

• Hallucinations

  • Seeing, hearing, feeling, smelling, tasting something that is not really there

  • Can involve misperception of real sensory information

  • Auditory hallucinations are most common, and are perceived as different from the thoughts of the patient

• Delusions

  • Implausible beliefs, based on misinterpretation of perceptions or experiences

  • Variety of themes are common (religious, persecutory, referential, somatic, grandiose)

  • Delusion versus strongly held belief?

• Disorganized thoughts and speech

  • Considered to be the fundamental feature of schizophrenia

  • Thoughts are assumed to be reflected by speech

  • Loose associations, tangentiality, “word salad”

  • derailment - a pattern of spontaneous speech that tends to slip off track and in which the ideas expressed are either obliquely related or completely unrelated

  • tangentiality - the patient will reply to a question in an oblique or irrelevant manner

• Disorganized behaviour

  • Problems in goal directed behaviour

  • Difficulties performing daily activities, dressing inappropriately, clearly inappropriate behaviour, un-triggered or unpredictable agitation

  • However, even when a behaviour is disorganized, there is often a purpose behind it

psychotic disorders: catatonic and negative symptoms

• Catatonic motor behaviour

  • Marked decrease in reactivity to the environment

  • Catatonic stupor (unawareness)

  • Catatonic rigidity (rigid posture and resistance to being moved)

  • Catatonic negativism (resistance to instructions)

  • Catatonic posturing (inappropriate or bizarre postures)

  • Catatonic excitement (purposeless or unstimulated excessive motor activity)

• negative symptoms

  • Avolition – a lack of motivation to engage in self-initiated and meaningful activity, including the most basic of tasks, such as bathing and grooming  

  • Alogia – refers to reduced speech output; in simple terms, patients do not say much  

  • Asociality – social withdrawal and lack of interest in engaging in social interactions with others  

  • Anhedonia – expresses little interest in what most people consider to be pleasurable activities, such as hobbies, recreation, or s*xual activity  

  • Affective flattening - reduced range and expression of emotions

  • Cognitive dysfunction - severe problems with executive
    functioning, memory, and attention

schizophrenia diagnostic criteria

• Two or more of the following for significant amount of time in a
  one month period:

  • Delusions

  • Hallucinations

  • Disorganized speech

  • Grossly disorganized or catatonic behaviour

  • Negative symptoms

• Only one symptom needed if delusions are bizarre or if hallucinations keep a running commentary of
  thoughts/behaviour or if two or more voices converse with
  each other

• One or more areas of functioning are markedly below level
  achieved before onset of the illness

• Disturbance lasts for at least six continuous months

• Not due to schizoaffective disorder, substance use, medical
  condition, or autism

Schizophrenia

• Diagnosis is based on reported or observed symptoms, although many of the symptoms by definition take place in the patient's mind

• Detailed observation of behaviour, speech, and cognition are important

• Cognitive functioning and eye tracking are two possible methods that can assist in diagnosis, though are never used in isolation

  • eye-tracking - may be related to abnormal perception, as well as social/emotional functioning

• 1% lifetime prevalence

• 1/12 of hospital beds in Canada are used for schizophrenic patients

• Equal prevalence in males and females, but average age of onset differs (males = 18-25, females = 25-35)

• More common is lower status social groups, which could in part reflect social drift

• Elevated co-morbidity of substance abuse disorders, OCD, panic disorder, mood disorders

• Clinicians tend to diagnose schizophrenia more frequently in
  patients of African descent

  • Clinician bias

  • Different prevalence of substance abuse, depressive symptoms

  • Delay in seeking care

biological etiology of schizophrenia

• Concordance rate of 30-50% in monozygotic twins, ~10% in dizygotic twins.

• Heritability is at least 0.8, and higher if considering individual symptoms or traits (broader phenotype).

• Schizophrenia has a higher prevalence in individuals whose mothers had pregnancy or birth complications

• Diathesis-stress model

  • Genetic abnormalities lead to brain dysfunctions, which lead to tendency to misperceive information, including own thoughts

  • Unrewarding social experiences lead to withdrawal

• Larger lateral and third ventricles

• Structural abnormalities reported in the medial temporal lobe, superior temporal gyrus, orbitofrontal cortex, parietal cortex, basal ganglia, corpus callosum, thalamus, and cerebellum

• Abnormal dopamine levels or binding

  • Anti-psychotic medication affects binding of the D2 receptor subtype

  • Psychotic mimicking symptoms in cocaine use

• Deficits in monitoring the source of their own thoughts; they seem to be coming from outside of the self or in another voice

  • Underactive secondary sensory areas of the brain (Wernicke’s area)

  • Weaker connections between temporoparietal region, cingulate, and amygdala

environmental etiology of schizophrenia

• Cannabis and psychosis

  • Cross-sectional studies – compelling evidence that higher users are more likely to have psychosis

  • Lab experiments – strong evidence that short term effects of marijuana use can mimic some psychotic symptoms

  • Longitudinal studies –moderately strong evidence that early marijuana use increases the risk of developing psychosis

• Cannabis is thought to increase the sensitivity of the dopaminergic system

social-cognitive etiology of schizophrenia

• Predisposition to auditory imagery

  • Lower threshold for imaging; images seem real or almost real

  • Disinhibition: The normal restraints on involuntary imaging are weak

• Externalizing bias

  • The tendency to ascribe unusual psychological experiences to an external agent reinforces the belief in external origin

• Deficient reality testing

  • Poor detection and correction of errors, overconfidence in judgment, and absence of reappraisal allow initial belief in the external origins to remain uncorrected

• Reasoning Biases

  • Circular reasoning and conclusions derived from emotion-based and somatic-based reasoning sustains belief in external origin

  • Misinterpretations and confirmatory bias serve to reinforce beliefs

  • Self reference bias: “Centre stage of a drama in which all happenings are about them”

  • Safety behaviours result in an inability to disconfirm beliefs

  • Behaviour of others can confirm beliefs

treatment for schizophrenia

• Antipsychotic medication

  • Thought to act by reducing the levels of dopamine in the brain

  • Some serious side effects, especially with long use and particularly for the older (first generation) antipsychotics

  • Regular medication accessibility and compliance are essential

• Psychosocial approaches

  • Reintegration and support in the community, especially case management

  • Intervention with family: most cost effective approach if appropriate

  • Treatment of mood, substance use, and cognitive issues

  • CBT is sometimes used but evidence that it improves outcomes is weak

• WHO ISoS

  • A series of longitudinal studies over the past several decades conducted across the world (10-12 countries) found some evidence of better outcomes in less developed countries

  • Complete remission and periods of unimpaired functioning were higher in developing countries, though the proportion of people with continuous unremitting symptoms was also higher

  • Outcomes were particularly positive in rural Nigeria, where access to Western psychiatric services is limited

  • To date there is no clear explanation for this finding

other psychotic disorders

• Schizoaffective disorder

  • A period of time in which criteria are met for a mood disorder and symptoms of schizophrenia, but with psychotic symptoms present when there are no mood symptoms

• Schizophreniform disorder

  • Exact same diagnostic criteria as schizophrenia but with a shorter duration

• Brief psychotic disorder

  • At least one symptom of psychosis, but for less than one month, with eventual full return to premorbid functioning

• psychosis vs mania

  • Although the first ever distinct mental illnesses to be defined by Kraeplin were mania and psychosis, it can be difficult to differentiate between them

    • Flight of ideas vs disorganized speech

    • Grandiosity vs grandiose delusions

    • Depressive symptoms vs negative symptoms

  • Depression usually precedes mania, but less often psychosis

  • Onset is usually sudden in bipolar, insidious in psychosis (with socially withdrawn behaviour)

  • Family history of one or the other

shared psychotic disorder

• Shared psychotic disorder (Folie a Deux) was a formal diagnosis in DSM-IV, now listed under “other specified”

• A delusion that develops in an individual who is involved in a close relationship with another person (the “inducer” or “primary case”)

  • Siblings, close friends, romantic partners, physician/patient (rare!)

• The individual shares the delusion in whole or in part

• Most common diagnoses in the inducer are schizophrenia and delusional disorder, and they tend to be more dominant in the relationship

• Can occur in groups larger than two people (ie: families, cults)

  • A somewhat similar phenomenon can occur in the population (“mass hysteria” and “Mandela effect”)

delusional disorder

• Presence of one or more delusions that last at least one month

• Hallucinations are absent or not prominent

• Functioning is impaired by the delusions (but not by other psychotic behaviour) and behaviour is not obviously bizarre

• Subtypes:

  • Jealous, Grandiose, Erotomanic, Persecutory, Somatic, Mixed, Unspecified

  • With bizarre content

• Most common subtypes are persecutory (48%), undifferentiated (23%), jealous (11%), mixed (11%), somatic (5%)

• 42% have personality disorder diagnosis (mostly paranoid personality disorder)

  • No clear-cut, persisting delusional beliefs in paranoid personality disorder

• Lowest level of functioning among erotomanic and grandiose subtypes

• Among stalkers, negative relationship between psychosis and risk of violence

violence and psychosis

• Violation of social norms is part of our definition of abnormality because social norms allow us to predict the behaviour of others

  • And we can fear unpredictability even when the behaviour is not dangerous

• When we see something that is consistent with our schemas (unpredictable = dangerous) we are much more likely to pay attention to and remember it, and that reinforces our schemas

• While the vast majority of individuals with schizophrenia are not dangerous, there is a slightly greater incidence of violence by
  people with schizophrenia compared to the general population

  • This is mostly related to severity of psychotic symptoms, relatively more positive than negative symptoms, and the presence of other comorbid conditions

  • The types of violent offences committed by those with schizophrenia are more or less the same as those committed by the general population

• Fear of stigma (including fear of being labeled as violent) probably reduces treatment seeking

• It also probably reduces people’s willingness to report being the victim of a crime, which we definitely know is higher in those with major mental illness

neurotransmitters

• The neurotransmitter dopamine has been found to be heavily related to the disorder 

  • Increased dopamine levels can produce schizophrenia-like symptoms and drugs that block dopamine activity can reduce the symptoms  

  • Dopamine hypothesis – proposed that an overabundance of dopamine or too many dopamine receptors are responsible for the onset and maintenance of the disorder  

  • An overabundance of dopamine in the limbic system may be responsible for some symptoms, such as hallucinations and delusions, whereas low levels of dopamine in the prefrontal cortex might be responsible primarily for the negative symptoms (avolition, alogia, asociality, and anhedonia) 

• In recent years, newer antipsychotic medications used to treat the disorder work by blocking serotonin receptors  

brain anatomy

• People with this disorder have enlarged ventricles, which are the cavities within the brain that contain cerebral spinal fluid  

  • Larger than normal ventricles suggests that various brain regions are reduced in size, thus implying that the disorder is associated with a loss of brain tissue  

• Many people display a reduction in grey matter (cell bodies of neurons) in the frontal lobes, and many show less frontal lobe activity when performing cognitive tasks