Schizophrenia

Schizophrenia (“splitting of mind”): a split between the emotional and intellectual

aspects of experience

Higher Prevalence:

Urban Areas: Stress, social isolation, drug use. Cannabis-Using Regions Scandinavian Countries Low/Middle-Income Countries

Schizophrenia Gender: Way more prevalent in males

Schizophrenia diagnosis: Delusions (unjustifiable beliefs, usually of a social nature) Hallucinations (false sensory experiences, such as hearing voices

when alone)  Disorganized speech (rambling or incoherent) Grossly disorganized behavior Weak emotional expression, speech, and socialization

Similar conditions to schizophrenia:Substance abuse, Brain damage, Undetected hearing deficits, Huntington’s disease, Nutritional abnormalities

Schizophrenia Genetics: Definitely is heritable (Rare genes that greatly increase chances Neuregulin, Disrupted in Schizophrenia)

Neurodevelopmental Hypothesis: Abnormalities occurred in prenatal or neonatal nervous system development can produce abnormalities in the developing brain that predispose to schizophrenia.

Two-Hit Hypothesis: Combination of a genetic predisposition and impacts from the

environment in prenatal/neonatal development, later in life, or both. 

First Hit Genetic mutations, prenatal infections, obstetric Complications. 

Second Hit Cannabis use during adolescence, chronic stress, urban living.

Brain Abnormalities in schizophrenia: Larger ventricles, decreased brain matter, smaller hippocampus and prefrontal cortex, reduced cortical connectivity

Dopamine Hypothesis: Positive symptoms are caused by over-activity of synapses between DA neurons of the ventral tegmental area (VTA) and nucleus accumbens and amygdala (Mesolimbic)

First generation Antipsychotic drugs: Blocks dopamine (2 major pathways mesolimbocortical and the basal ganglia) Leads to a movement disorder

Second generation antipsychotic drugs: Focused on blocking serotonin but resulted in weight gain

Third Generation antipsychotic drugs: Blocks the dopamine precisely