Chapter 17B: Schizophrenia

Schizophrenia

Mental disorder characterized by dissociative thinking, delusions, hallucinations, and other bizarre behaviors

1, 1/3

Schizophrenia affects _% of people worldwide, __ of homeless affected

Positive Symptoms

Abnormal behaviors gained with schizophrenia (i.e. hallucinations, delusions, disordered thinking, excited motor behavior)

Negative Symptoms

Loss of normal function with schizophrenia (i.e. flat affect, anhedonia, weak social relationships, reduced motivation, alogia (decreased speech)

Cognitive Symptoms

Deficits in attention, learning, memory, rational problem solving, motor

DISC1

Rare gene mutation increasing schizophrenia risk

Older Fathers

Increased risk to have schizophrenic child due to sperm mutations or epigenetics

Changes

Uterine development ___ risk of identical twins

Monochorionic

Same placentas, similar toxin exposure // 60% risk for second twin

Dichorionic

Different placentas, different toxin exposure // 10% risk for second twin

Seasonality Effect

Increased incidence in people born during late Winter and early Spring

Influenza

Exposure to viruses or ___ interfere with developing fetus

Large Cities

Increase incidence per population unit than rural areas // increased exposure to viruses, pollutants, stress (risk factor)

Prenatal Malnutrition

Lower birth weight/motor issue (risk factor)

Complications

Mother with diabetes, Rh-factor incompatibility, preeclampsia demonstrate ___ during pregnancy (risk factor)

Substance Abuse

Tobacco during pregnancy (risk factor)

Early behavioral anomalies

Abnormal motor movements as child, higher negative affect, less sociability

Negative, cognitive, positive

Timeline for symptom development (1) ___ --> (2) ___ --> (3) ___

Hypofrontality

Gray matter loss to frontal lobe, enlargened ventricles

Wisconsin Card Sorting Task

Frontal cortex less active during cognitive tasks involving accuracy

Faster

Loss of gray matter is ___ with age

Helps

DA antagonist ___ mesolimbic pathway

Hurts

DA antagonist __ mesocortical pathway

Mesolimbic Pathway

VTA release of dopamine to Nucleus accumbens is OVERACTIVE

Positive

Overactive mesolimbic pathway is thought to underlie ___ symptoms

Dopamine Hypothesis

Increased dopamine activity is positively correlated with positive schizophrenic symptoms

Dopamine Antagonists

Eliminate positive symptoms (i.e. antipsychotics)

Dopamine Agonists

Produce positive symptoms (i.e. Amphetamine, cocaine, etc)

More

Schizophrenics have ___ dopamine receptors

Tardive Dyskinesia

Excessive movement in which DA receptors become supersensitive --> 1/3 of patients have this as a permanent side-effect

Mesocortical Pathway

VTA release of dopamine to Prefrontal cortex is UNDERREACTIVE

Negative and Cognitive

Hypofrontality of mesocortical pathway is thought to underlie ___ ___ ___ symptoms

All

DA overactivity fails to account for all schizophrenic symptoms (i.e. negative and cognitive)

Reverse, worse

DA receptor blockers fail to ___ cognitive or negative symptoms, thus making these ___

Glutamate Hypothesis

Underactive NMDA receptors on VTA neurons and a decrease in glutamate in cerebrospinal fluid

Glu Antagonists

Produce all 3 symptoms types (i.e. PCP, ketamine)

Lobotomies

Surgical separation of part of the frontal lobe

Chlorpromazine

First typical antipsychotic in 1950s

Conventional (Typical) Antipsychotics

Antagonist to ONLY DA receptor subtypes (i.e. chlorpromazine, thioridazine, haloperidol)

Atypical Antipsychotics

Antagonists to DA and 5-HT receptor subtypes (i.e. aripiprazole, clozapine, quetiapine, risperidone)

True

Current antipsychotic treatments are empirically inadequate (T/F)

Moslimbic, mesocortical

Atypical antipsychotics act as a partial agonist by reducing DA in the ___ area and increasing DA in the ___ area

Cognitive

___ Symptoms are not required for diagnosis of Schizophrenia