Slides: Schizophrenic Mind

Types of Negative symptoms of SCZ (5 As)

-Anhedonia = inability to feel pleasure -Avolition= lack of energy for routine or goals -Alogia= lack meaningful speech -Asociality= impairment in social relationships, few friends -Flat Affect= no emotion response, lifeless eyes, toneless voice (outward)

schizophrenia

>"split mind" >split from the emotional and cognitive aspects of personality >PSYCHOTIC DISORDER > A severe, progressive mental disorder in which thinking and emotion are so impaired (so uncoupled) that the individual is seriously out of contact with reality.

Models of schizophrenia (4)

>Diathesis-Stress (genetic/psychological/biological/situational+stressors) >Dysregulation Hypothesis (DA/5-HT;glutamate; GABA) >Neurodevelopmental >Sociocultural

Positive symptoms SCZ

>Distortions or excesses of normal functioning -delusions -hallucinations -disorganized speech -thought disturbances -motor disturbances >Positive symptoms are generally more responsive to treatment than negative symptoms

The Dopamine Hypothesis

>Disturbed functioning in dopamine system (i.e., excess dopamine activity in mesolimbic pathway: VTA nucleus accumbens and amygdala)

Delusions

>POSITIVE symptoms >false belief despite evidence >individual with mania or delusional depression might have >SCZ= more bizarre (highly implausible) -Delusion of grandeur (famous person from the past) -Delusions of control (external force takes control or behavior/ thought) -thought broadcasting (thoughts being transmitted) -thought withdrawal (thoughts being removed) -delusion of reference (always center of attention) -Delusions of persecution (target of evil)

Hallucinations

>POSITIVE symptoms >Perceptual Distortions >often the first symptoms in many brain illnesses -sensory experiences in the absence of any stimulation from the environment >Sensory modality may be involved: -auditory -visual -olfactory -tactile -gustatory

Supportive evidence of dopamine hypothesis

>Phenothiazines reduce dopamine activity and psychotic symptoms are reduced; >L-Dopa and amphetamines increase dopamine activity and can produce psychotic symptoms

Schizophrenia, Consciousness, and Self

>Schizophrenia is disorder of consciousness and of the self, specifically of our subjective experience or first person perspective on the world, involving a loss of self-other distinction

Social class and schizophrenia

>Schizophrenia is most common at lower socioeconomic status levels -BREEDER hypothesis: stressors associated with low SES increase the likelihood schizophrenia will develop -Downward drift Theory: individuals with schizophrenia drift into low SES areas because they cannot function in other environments

SZC as disorder of development

>develop during late adolescence >slow emergence of brain abnormalities >combination of genetic and environment -no single gene -have experienced combinations of adverse events

Problems with hypofrontality

>participants chronic patients on heavy neuroleptic medications >some evidence indicates antipsychotic medications influence cerebral blood flow even in patients who are currently medication free

Schizophrenia, Consciousness, and Self

Schizophrenia is disorder of consciousness and of the self specifically of our subjective experience or first person perspective on the world, involving a loss of self-other distinction Hyperreflexivity (exaggerated self-consciousness; reduced automatization) Diminished sense of self-groundedness; loss of embodiment (e.g. loss or mirroring) Loss of salience or stability with which objects stand out in an organized field of awareness

Type I vs Type II Schizophrenia

Type I: Acute schizophrenia -Positive symptoms -More responsive to neuroleptics (anti-psychotics) Type II: Chronic schizophrenia -structural abnormalities in brain -less responsive to pharmacotherapies

Problems with DA hypothesis

>About 25% of people with schizophrenia are not responsive to antipsychotic medications affecting dopamine. >Other effective medications (Clozapine) work primarily on serotonin, rather than dopamine, system. >Antipsychotic drugs block dopamine receptors quickly, but relief from symptoms is not seen for weeks. PCP produces symptoms similar to schizophrenia by blocking the NMDA glutamate receptor.

Models of schizophrenia (4)

>Diathesis-Stress (genetics+stressors) >Dysregulation Hypothesis (DA/5-HT;glutamate; GABA) >Neurodevelopment >Sociocultural

Neurobiology of schizophrenia

>General abnormalities -frontal lobe -temporal love -fronto-temporal connections >Abnormalities are at the cellular level

Schizophrenia, Consciousness, and Self 3 specific things

>Hyperreflexivity (exaggerated self-consciousness; reduced automatization) >Diminished sense of self-groundedness; loss of embodiment >Loss of salience or stability with which objects stand out in an organized field of awareness

Hypofrontality Finding

>Low relative glucose metabolism frontal areas >Low frontal lobe activity may account for NEGATIVE symptoms of schizophrenia >less frontal lobe activity

Problem with structural abnormalities

>differences relatively small compared with control groups, SCZ fall within normal ranges >reported in 6-40 % in variety of studies >reported in patients with mood disorders

Negative symptoms SCZ

>endure beyond an acute episode of SCZ >associated with poor prognosis >negative symptoms might be SECONDARY to medication / institutionalization >LOSS of behaviors (loss of affect, can't maintain social contacts, impaired decision making, can't maintain attention)

Pyramid cells schizophrenia

>normal= organized >schizo= disorganized

Two types of consciousness usually experienced

-Ordinary, waking consciousness -Dreaming, sleeping

Cognitive defects in SCZ

-Short and long-term -memory problems -Poor attention span -Easy distractibility -Illogicality -Pressured speech -Lack of insight, judgment, and lack of problem-solving -Inability to think abstractly

Interpenetration of two processes of ordinary consciousness

-The brain encodes outside events in their setting, creating a sense of "other" -The brain sets us up as central agency for experiencing these events

Structural Abnormalities in Schizophrenic Brains (6)

-less than average weight -Enlarged ventricles -Decreased volume in frontal + temporal lobes -Reduction in the number of neurons in the prefrontal cortex -abnormal cellular structure in the prefrontal cortex and hippocampus -Hypo-frontality during card sorting