Exam 1 Key Points: Schizophrenia and Psychosis

Flashcards covering key concepts related to schizophrenia and psychosis, including biological factors, dopamine hypothesis, other leading hypotheses, diagnostic criteria, and relevant brain areas and components of the immune response.

Enlarged Ventricles

Common finding in twins with and without schizophrenia; ventricles expand to fill the void left by loss of gray matter.

Reduced Neurophil Hypothesis

Schizophrenic patients have the same amount of neurons as healthy people but are packed together (increased density) in a smaller space; results from reduced cell size, less branching, and decreased spine function.

Cognitive Dysfunction

Problems with attention, memory, and executive function; most detrimental aspect of schizophrenia and best predictor of long-term outcome.

Hypofrontality

Reduced activity in the frontal cortex, potentially explaining cognitive impairment in schizophrenia.

GABA neurons

Decreased expression of important genes that might impair function of the cortex is seen in schizophrenic patients (NOT deficient in total number).

Dopamine Hypothesis of Schizophrenia

Hyperactivity of dopamine D2 receptor neurotransmission in subcortical and limbic brain regions contributes to positive symptoms; hypo-functionality of dopamine D1 receptor neurotransmission in the prefrontal cortex contributes to negative and cognitive symptoms.

NMDA Receptor Hypothesis

Low glutamate activity at NMDA receptors due to abnormal synapse development, particularly on GABA interneurons in the prefrontal cortex.

Reduced Neuropil Hypothesis

Schizophrenic patients have the same amount of neurons as healthy people but are packed together in a smaller space; loss of richness of dendritic connections may cause reduced gray matter.

Reelin

Protein expressed by GABA interneurons; reduced in schizophrenia and necessary for neuronal migration, branching, and synaptogenesis.

Genetics of Schizophrenia

Closer relationship to someone with schizophrenia increases the likelihood of developing the illness; monozygotic twins have a 50% chance of both having the illness.

Environmental Factors of Schizophrenia

Include urban setting, prenatal complications (maternal infection, obstetric complications), famine (maternal starvation, lack of folate), and adverse family environment.

Methylation

Adding methyl groups limit gene expression; Reelin DNA of schizophrenic patients is more likely to be methylated.

Nigrostriatal Pathway

Projects from the substantia nigra to the basal ganglia; controls motor function and movement.

Mesolimbic/Mesostriatal Pathway

Projects from the midbrain VTA to the nucleus accumbens; involved with pleasure, euphoria, and hallucinations/delusions of psychosis.

Mesocortical Pathway

Projects from the midbrain VTA to the prefrontal cortex; mediates cognitive and affective symptoms.

Tuberoinfundibular Pathway

Projects from the hypothalamus to the anterior pituitary; controls prolactin secretion.

Superior Temporal Lobe

Activated during auditory hallucinations, as shown by fMRI studies.

Delusional Disorder

Characterized by at least 1 month of delusions but no other psychotic symptoms; functioning is not markedly impaired.

Brief Psychotic Disorder

Duration of an episode is at least 1 day but less than 1 month, with eventual full return to premorbid functioning; includes delusions, hallucinations, disorganized speech, or catatonic behavior.

Schizophreniform Disorder

An episode of the disorder lasts at least 1 month but less than 6 months; includes delusions, hallucinations, disorganized speech, catatonic behavior, or negative symptoms.

Schizophrenia

Continuous signs of the disturbance persist for at least 6 months, including at least 1 month of active-phase symptoms; significant impairment in functioning.

Schizoaffective Disorder

An uninterrupted period of illness during which there is a major mood episode concurrent with Criterion A of schizophrenia; delusions or hallucinations for 2 or more weeks in the absence of a major mood episode.

Prefrontal Cortex (PFC)

Located in the frontal lobe; involved in planning complex cognitive behavior, personality expression, decision making, and moderating social behavior.

Hippocampus

Folded structure incorporated in the medial region of the temporal lobe; important in regulating emotional responses and in storing long-term memories.

Amygdala

Lies within the temporal lobe anterior to the hippocampus; plays important roles in emotion and behavior, particularly the processing of fear.

Hypothalamus

Command center of the brain; controls basic functions such as eating, drinking, sleeping, sexual behavior, emotional responses, and temperature regulation.

Cerebellum

Sits on top of the brainstem at the back of the skull; involved in coordination/movement, sensation, cognition, and impulse control.

Cellular (WBCs)

Macrophages and neutrophils are frontline defenders; neutrophils circulate in the blood, ready to come to the aid of defenseless tissue; macrophages patrol the perimeter of the skin and mucous membranes cleaning up debris and searching for bad guys.

Humoral (antibodies)

T cells, B cells: T-cells multiply and head off to attack that specific remnant of the invader; B-cells start producing antibodies.

complement (‘little torpedoes’)

Made up of numerous proteins circulating in the blood; when activated by foreign protein (e.g found on bacteria); they lock onto the bacteria and accumulate; can drill hole into the cell wall allowing fluid to pour in the bacteria to explode

Cytokines

Hormones of the immune system; primary function is to activate and guide immune cells; orchestrate direction, magnitude, and duration of inflammatory response.

Hypothalamic-Pituitary-Thyroid (HPT) Axis

Thyroid hormones are involved in maintaining optimal metabolism in nearly every organ system. Integral to temperature regulation

Hypothalamic-Pituitary-Adrenal (HPA) Axis

The HPA axis controls the synthesis and release of corticosteroids which are derived from dietary cholesterol in the adrenal cortex and include the mineralocorticoids, sex hormones, and glucocorticoids.