Schizophrenia Study Guide

Schizophrenia Definition Medical disorder characterised by disruptions in thought processes, perceptions, emotional responsiveness and social interactions. Causes • • • • • Multifactorial Genetic - Monozygotic twins - Both parents - Dizygotic twins Important affected genes: - DISC1 - NRG1 - DTNBP1 - COMT: ➔Codes of postsynaptic intracellular enzyme COMT -> methylation and degradation of catecholamine, dopamine, epinephrine and norepinephrine. ➔Cannabis users - DAOA - GRM3: ➔ Protein coding gene associated with bipolar affective disorder ➔Increases risk of schizophrenia, alcohol dependence disorder and bipolar disorder. - BDNF - NOS1AP: ➔Codes of nitric synthase -> in high concentrations in brain inhibitory neurons ➔NO -> intracellular messenger - RELN Neurochemistry/dopamine hypothesis - Excess dopamine in the mesolimbic pathway -> positive symptoms - Decrease dopamine in the prefrontal cortex -> negative and cognitive symptoms - GABA, glutamate and Ach are also thought to be involved. Neuroanatomy - Decreased frontal lobe function - Asymmetric temporal/limbic functions - Decreased basal ganglia function - Subtle changes in the thalamus - Cortex - Corpus callosum - Ventricles - Cytoarchitectural abnormalities • • • • • • Neuroendocrine - Abnormal growth hormone - Prolactin - Cortisol - ACTH Neuropsychology - Global defects seen in attention, language, memory -> suggest disturbed connectivity of neural networks Environment - Indirect cannabis use - Geographical variance - Winter birth season - Obstetrical complications ➔Children more likely to develop - Prenatal viral exposure Malnourished women Viral illnesses in pregnancy -> their children are at a higher risk Drugs - Marijuana Pathophysiology • • • Anatomic abnormalities - Larger ventricles ➔Lateral - Decreased brain volume in medial and temporal areas ➔In both grey and white matter - Changes in the hippocampus - Abnormalities in the network of neocortical and limbic regions interconnecting the white matter tracts ➔Seen in MRI Neurotransmitter system abnormalities - Abnormalities of the dopaminergic system - Mesocortical system -> hypodopaminergic activity -> negative symptoms - Mesolimbic system -> hyperdopaminergic activity -> positive symptoms - Both of above may co-exist - NE, serotonin, and GABA also involved. Inflammation and immune system - Overactivation of the immune system -> overexpression of proinflammatory cytokines -> activate kynurenic pathway -> tryptophan metabolised into kynurenic and quinolinic acids -> dysregulate NMDA receptor activity -> may also be involved in dopamine regulation -> alteration of brain structure -> alteration of brain function ➔E.g. from prenatal infection, postnatal stress - Insulin resistance and metabolic disturbances ➔Common schizophrenia patients ➔Linked to inflammation Diagnosis DSM-V Criteria A. Two (or more) of the following, each present for a significant portion of time during a 1month period (or less if successfully treated). At least one of these must be (1), (2), or (3): 1. Delusions 2. Hallucinations 3. Disorganized speech (e.g., frequent derailment or incoherence) 4. Grossly disorganized or catatonic behaviour 5. Negative symptoms (i.e., diminished emotional expression or avolition) B. For a significant portion of time since the onset of the disturbance, level of functioning in one or more major areas (e.g., work, interpersonal relations, self-care) is markedly below the level achieved prior to the onset (or when the onset is in childhood or adolescence, there is failure to achieve the expected level of interpersonal, academic, or occupational functioning). C. Continuous signs of the disturbance persist for at least 6 months. This 6-month period must include at least 1 month of symptoms (or less if successfully treated) that meet Criterion A (i.e., active-phase symptoms) and may include periods of prodromal or residual symptoms. During these prodromal or residual periods, the signs of the disturbance may be manifested by only negative symptoms or by two or more symptoms listed in Criterion A present in an attenuated form (e.g., odd beliefs, unusual perceptual experiences). D. Schizoaffective disorder and depressive or bipolar disorder with psychotic features have been ruled out because either 1) no major depressive or manic episodes have occurred concurrently with the active-phase symptoms, or 2) if mood episodes have occurred during active-phase symptoms, they have been present for a minority of the total duration of the active and residual periods of the illness. E. The disturbance is not attributable to the physiological effects of a substance (e.g., drug of abuse, medication) or another medical condition. F. If there is a history of autism spectrum disorder or a communication disorder of childhood onset, the additional diagnosis of schizophrenia is made only if prominent delusions or hallucinations, in addition to the other required symptoms of schizophrenia, are also present for at least 1 month (or less if successfully treated). - Specifiers: type of episode (e.g., first episode, multiple episodes, continuous), in acute episode/partial/full remission, with catatonia, current severity based on quantitative assessment of primary symptoms of psychosis. Treatment and management Pharmacological • • Anti-psychotics: - Newer antipsychotic drugs -> block both dopamine and serotonin receptors. - Clozapine: ➔Possibly the most effective agent ➔Weak D2 antagonist - Acute treatment and maintenance: ➔Risperidone, aripiprazole, haloperidol, paliperidone ➔If resistant -> use clozapine ➔Maintenance treatment for at least 1 to 2 years after first episode ➔Maintenance treatment for at least 5 years after multiple episodes ➔Relapse causes severe deterioration - Long acting injectables ➔LAI or depot ➔ Shown to be mor effective in reducing relapse and rehospitalisation compared with oral alternatives. Adjunctive: - May or may not be used Psychosocial interventions for psychosis including schizophrenia • • • • • • • • • • • • • To patients, family members, cares or significant others Accommodation support Adherence therapy Behavioural therapy - E.g. for negative symptoms Case management services Cognitive remediation for cognitive deficits - E.g. for patient with cognitive features Coping strategies enhancement Disability support Motivation interviewing for patients with problem substance abuse Social interventions - Combats isolation Social skills training Support for employment and education programs Assertive community treatment - For people with severe mental health conditions - Involves a range of home-based treatment support services. Psychoeducation • Educating the patient, their family or cares about: - The psychotic disorder - Causes and symptoms - - Characteristic early symptoms and signs of relapse Strategies to prevent relapse Treatment ➔Including advice about the importance of anti-psychotic therapy and monitoring for preventing and addressing antipsychotic adverse effects The roles of the mental healthcare system ➔Includes both workers and relevant mental health legislations Others • • • Motivational interviewing for problem substance use Social skills training Supported employment and education