Psychiatry Flashcards
Define psychosis
Interruption from reality
- may affect thought process, thought content, behaviours and/or perceptions
- manifested by delusions, hallucinations, disorganized thoughts and behaviours, or failed reality testing
- > sx not dx
Define delusion
Fixed false beliefs that fall outside cultural norms
What is schizophrenia characterized by?
- positive sx - delusions, hallucinations
- negative sx - affective blunting, anhedonia, abolition, alogia
- cognitive impairment - attention, concentration, processing speed, learning, memory, executive function
Age of onset of psychosis in schizophrenia?
late teens to mid-30s
- earlier for men
Genetic risk of schizophrenia?
50% when both parents affected
60-84% monozygotic twins
Environmental factors re: schizophrenia?
- perinatal events
- obstetric complications
- social stressors
Neurotransmitters re: schizophrenia
- hyperdopaminergic state in D2 striata system = + sx
- hypodopaminergic state in prefrontal D1 system = cognitive deficits
- monoamine receptors (serotonin, histamine, muscarinic, alpha-adrenergic) = - sx
- Ach related to high use of tobacco
- glutamate and GABA related to some behavioural and cognitive sx
Most common anatomical finding in schizophrenia?
- enlargement of the ventricles
+/- reduced frontal lobe activation - functional circuit disruption (vs. localized dysfunction)
Ddx psychosis -> psychotic disorders
- schizophrenia
- shizophreniform
- brief psychotic disorder
- delusional disorder
- schizoaffective disorder
Ddx psychosis
Psychiatric
- psychotic
- mood + psychotic features (MDD, bipolar I)
- OCD
- mental retardation
- autism spectrum
- personality (Schizotypal, schizoid, borderline, paranoid)
- malingering, factitious
Substances/medications
- substance abuse
- rx medications (e.g. steroids)
- toxins
General medical conditions
- CNS - lesions, infections, seizures, strokes
- Systemic illness - autoimmune, metabolic, endocrine, vitamin deficiency, sepsis
Baseline investigations for schizophrenia
- CBC, lytes, Cr, BUN, LFTs, TSH
- fasting plasma glucose
- lipid panel
- toxicology screen
- syphilis, HIV
+/- head CT, MRI (re: structural brain abnormalities)
ECG
clinical screening for chromosome 22q11
Timeline re: brief psychotic vs. schizophreniform vs. schizophrenia
<1mo = brief psychotic disoder 1-6mo = schizophreniform disorder >6mo = schizophrenia
Diagnosis for pt with only delusions but not much functional impairment?
Delusional disorder
Diagnosis for pt with psychosis plus mood sx with periods lasting at least 2wk of only psychosis and no mood BUT mood sx at least half the time of illness?
Schizoaffective disorder
Diagnosis for pt with psychosis plus mood sx but NO periods of at least 2wk of only psychosis and no mood?
Depression with psychosis
Bipolar I with psychosis
Criteria A for schizophrenia
At least 2 of the following:
- delusions
- hallucinations
- disorganized speech
- disorganized behaviour
- -> at least 1 mo and with impairment lasting at least 6mo
Atypical antipsychotic advantages vs. disadvantages
- less chance of extrapyramidal sx and tardive dyskinesias
- increased metabolic s/e
When can clozapine be tried?
- after 2 failed trials of different antipsychotics (6-8wk optimized therapeutic dose)
What is the most efficacious medication to treat schizophrenia? What are the s/e?
Clozapine
- regular and consistent monitoring re: agranulocytosis, seizures, myocarditis
Typical antipsychotics
- indications
- CI
- adverse
High potency - haloperidol
- indications: positive sx, pregnancy
- CI: preexisting movement disorder/ TD
- adverse: higher risk EPS/TD; hyperprolactinemia
Low potency - chlorpromazine, thioridazine
- indications: positive sx
- CI: preexisting movement disorder/ TD
- adverse: lower risk EPS/TD; postural hypotension, sedation, anticholinergic (blind as a bat, mad as a hatter, dry as a bone, red as a beet, hot as a hare)
Atypical antipsychotics
- indications
- CI
- adverse
- E.g. olanzapine, resperidone, clozapine, quetiapine, aripiprazole
- indications: positive or negative or cognitive sx; preexisting movement disorders sensitivity (quetiapine or clozapine); treatment refractory (clozapine); suicidality (clozapine)
CI: diabetes (relative) - adverse: low risk EPS/TD; weight gain/ hyperglycemia/ hyperlipidemia/ diabetes/ sedation; agranulocytosis (clozapine - need weekly CBC x6mo then >biweekly CBC); prolonged QT interval (esp. quetiapine - need ECG monitoring)
Psychosocial treatment for management of psychotic/ thought disorders?
Supportive therapy
CBT
Define mania
Period of severe and sustained elevated mood that leads to disturbed behaviour and function
+/- psychotic sx
hypomania if elevation in mood less severe or more brief
Prevalence bipolar disorder and median age of onset
Bipolar I = 0.6%
Bipolar II = 0.4%
Subthreshold disorders = 1.4%
Median age of onset 25yr