Schizophrenia
Brief History
- Kraeplin (1919) came up with first definition (called it dementia praecox)
- Blueler (1950) introduced the term “schizophrenia” (Bleuler’s 4 A’s: Association, Affect, Ambivalence, and Autism)
- Schneider (1959) came up with 11 pathognomonic symptoms (Schneiderian First Rank Symptoms)
- Crow (1980) proposed that schizophrenia be divided into 2 major syndromes (Type I and Type II)
- Type I = domination of positive symptoms (Normal brain structure, Most intact neurocognitively, Relatively good response to treatment)
- Type II = domination of negative symptoms (Structural brain abnormalities, Impaired cognitive functioning, Poor response to treatment)
DSM-IV criteria (briefly)
- Characteristic Symptoms (two or more)
- delusions
- hallucinations
- disorganized speech
- grossly disorganized or catatonic behavior
- negative symptoms
- Social/Occupational Dysfunction
- work
- interpersonal relationships
- self-care
- Duration
- 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 being treated)
- Exclusion of schizoaffective and mood disorder
- Exclusion of substance/general medical condition
- If there is a relationship to a pervasive developmental disorder, schizophrenia is only diagnosed if prominent delusions or hallucinations are also present for at least a month
Etiology (Biological View)
- Genetics
- General population is 1%
- Identical twin = 48%
- Offspring of two schizophrenic parents = 46%
- Fraternal twin = 17%
- Sibling = 9%
- Half sibling = 6%
- First cousin = 2%
- Adoption studies
- Possible defects found on several chromosomes
- Biochemical Abnormalities
- Dopamine Hypothesis (Too much dopamine; Neuroleptics block dopamine receptors)
- Amphetamines prevent reuptake of dopamine, and individuals on amphetamines can display symptoms of schizophrenia
- Abnormal Brain Structure
- Smaller frontal lobes
- Smaller temporal lobes (decreased amygdale, hippocampus, and parahippocampal gyrus)
- Abnormalities in the limbic system and basal ganglia
- Enlarged ventricles (especially in Type II)
- Smaller amounts of cortical gray matter
- Abnormal blood flow in certain areas of the brain (especially frontal lobes)
- Viral Problems
- In vitro viral exposure that is activated by changes in hormones or other viruses
- Influenza exposure
- Pestiviruses (found in 40% of schizophrenics)
- Higher number of schizophrenics during the winter
- May explain why fraternal twin has a greater chance than a sibling
Neuropsychological Functioning
- Frontal lobe dysfunction
- Impaired attention including problems with filtering, problems distinguishing relevant from irrelevant information, selective attention is often impaired with increased information load, sustained and focused attention abilities are often poor.
- Problems with abstraction
- Problem solving deficits on WCST, CST
- Poor planning on the Clock Drawing, secondary to verbally mediated planning difficulties
- Memory deficits
- Impaired CVLT-II, WMS-III, BVRT
- CVLT research shows impairment in learning, recall, and recognition measures, but equal-to-normal retention of information over the delay (i.e., normal storage)
- Can have deficits on language tests
- In speech disordered schizophrenics (e.g., Disorganized Type), can have impaired BNT
- On the COWA, Schizophrenics produce more phonemic responses than category words
- Slower reaction time to both auditory and visual signal on the RT
Bipolar Disorder
DSM-IV Criteria of mania (briefly)
- Elevated, expansive, or irritable mood lasting at least one week
- Three or more of the following (four if mood is only irritable)
- Inflated self-esteem or grandiosity
- Decreased need for sleep
- More talkative or pressured speech
- Flight of ideas or racing thoughts
- Distractibility
- Increase in goal-directed activity
- Excessive involvement in pleasurable activities that have a high potential for painful consequences
- Significant stress or impairment
- All typical exclusions apply (not due to other psych, medical, substance D/O, etc.)
Bipolar I Disorder vs. Bipolar II Disorder vs. Cyclothymia (briefly)
- Bipolar I Disorder – Presence of mania and depression
- Bipolar II Disorder – Presence of depression and hypomania (no history of manic episodes)
- Cyclothymia – Two years of mood cycles, but events don’t meet criteria of depression or mania (less severe with shorter swings)
Etiology (Biological Model)
- Structural brain abnormalities (ventricular enlargement)
- Genetic factors (possible genetic links have been found on chromosomes 11 and X
- 40% chance for MZ twin to get it
- 5-10% chance of a close relative to get it
- 1% chance in the general population
- Neurotransitters
- High norepinephrine
- Serotonin can be implicated (low)
- Ion Activity
- Improper transportation of sodium and potassium ions between the outside and the inside of the neuron’s membrane
Neuropsychological Functioning
- General intellectual function is largely preserved in BD.
- Impairments when present are limited to acute episodes and to performance scores.
- Abnormalities in attention are seen in symptomatic patients and persist in remission in measures of sustained attention and inhibitory control.
- Verbal memory may be impaired even in euthymic patients, while visual memory deficits are variable depending on the tasks used.
- Executive functioning (planning, abstract concept formation, set shifting) are impaired in symptomatic patients, but it may be normal in fully recovered patients
Obsessive Compulsive Disorder
DSM-IV Criteria (briefly)
- Either obsessions or compulsion
- Insight at some point (If not, then subtype “poor insight)
- Marked distress, time consuming (>1 hour per day), or significantly impairs functioning
- If there is another Axis I disorder, O-C are not restricted to it
- Not due to substance use or medical disorder
Etiology (Biological Model)
- Structural abnormalities
- Orbital frontal cortex
- Caudate nucleus
- Cingulate gyrus
- Neurochemical: Possible down-regulation in both the number of serotonin receptors and release of serotonin
Neuropsychological Functioning
- Investigations generally agree on localization of dysfunctional areas (e.g., prefrontal and frontal regions, limbic system, basal ganglia).
- They disagree as to hemisphere and frontal lobe side impairment, involvement of other brain areas, pathophysiological connections, and impact of developmental phases and of concomitant cognitive and affective conditions.