Chapter 12

• The fifth edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, the DSM-5, provides a standardized system for diagnosing and classifying the major psychiatric illnesses according to current knowledge.
• Worldwide, between 15-20% of the population report psychiatric symptoms at some point in life, with North Americans positioned at the top end of this range.
• ~19% of the adult population in the United States experience psychiatric symptoms in the course of a year, and of this number more than 4% (equating to almost 10 million people) are so ill that they are unable to carry out major life activities.
• Rates of psychiatric symptoms among adults in the U.S. are higher for females than males, primarily because females are more likely to be depressed.
• Drug dependency and alcoholism are much more frequent in males.
• At the start of the 20th century, almost a quarter or the patients in mental hospitals suffered from so-called paralytic dementia, featuring sudden onset of delusions, grandiosity, euphoria, poor judgement, impulsive behavior, disordered thought, and physiological signs like abnormal pupillary restriction.
• Paralytic dementia was initially believed to be caused by "weak character" but postmortem studies have shown that it was actually from a physiological cause: syphilis.
• a false belief that is strongly held in spit of contrary evidence

  delusion
• a severe psychopathological disorder characterized by negative symptoms such as emotional withdrawal and flat affect, by positive symptoms such as hallucinations and delusions, and by cognitive symptoms such as poor attention span

  schizophrenia
• First rank symptoms of schizophrenia

  1. auditory hallucinations
  2. highly personalized delusions
  3. changes in affect (emotion)
• abnormal behavioral states that have been gained, such as hallucinations, delusions, and excited motor behavior(psychosis)

  positive symptoms of schizophrenia
• abnormalities resulting from the loss of normal functions, such as slow and impoverished thought and speech, emotional and social withdrawal, or blunted affect(emotional dysregulation & impaired motivation)

  negative symptoms of schizophrenia
• Parents and siblings of people with schizophrenia have a higher risk of developing schizophrenia than do individuals in the general population.
• problems with processing and acting on external information such as memory problems, poor attention span, difficulty making plans, poor social cognition (neurocognitive impairment)

  cognitive symptoms of schizophrenia
• Studies of adopted people confirm a strong genetic factor in schizophrenia. The biological parents of adoptees with schizophrenia are far more likely to have had this disorder than are the adopting parents.
• In identical (or monozygotic) twins, who derive from a single fertilized egg and thus share the same set of genes, if one of the twins develops schizophrenia, the other twin has a roughly fifty-fifty chance of also developing the disorder. But in fraternal (or dizygotic) twin pairs, who come from two fertilized eggs and thus share about 50% of their genes, just like any pair of siblings, this concordance (sharing of a characteristic) drops to about 17%.
• Even with identical twins, the concordance rate for schizophrenia is only about 50%., which tells us that genes alone cannot fully explain whether a person will develop schizophrenia.
• Often, the twin who goes on to develop schizophrenia has an abnormal

  developmental history, such as lower birth weight, more physiological distress in early life, and behavior that seems more submissive, tearful, and sensitive than that of the unaffected twin.
• Genetic analyses suggest that over 100 genes influencing the likelihood of schizophrenia are scattered across many different human chromosomes.
• Children fathered by older men have a greater risk of developing schizophrenia, which is though to be a result of them being the product of more cell divisions than the sperm of younger men, and therefore the sperm of older men having more opportunity to accumulate mutations caused by errors in copying the chromosomes.
• Schizophrenia usually appears during a time in life that many people find stressful—the transition from childhood to adulthood, when people deal with physical, emotional, and lifestyle changes.
• People living in a medium-sized city are about 1 1/2 times more likely to develop schizophrenia than people living in the country. The earlier in life a person begins living in the city, the greater the risk.
• Prenatal stress increases the likelihood that the baby will develop schizophrenia later in life. Likewise, is the mother and a baby have incompatible blood types, or the mother becomes diabetic during pregnancy, or if there is a low birth weight, the baby is more likely to develop schizophrenia.
• Birth complications that deprive the baby of oxygen also increase the probability of schizophrenia.
• Alteration of brain development in people with schizophrenia is indicated by the acceleration or the normal thinning of cortical gray matter, a result of synapse rearrangement.
• Most people with schizophrenia have enlarged cerebral ventricles, especially in the lateral ventricles.
• Because overall brain size does not seem to be affected in people with schizophrenia, the enlarged ventricles must come at the expense of brain tissue.
• Among people with schizophrenia, those with larger ventricles benefit less from antipsychotic drugs.
• A disabled version of the gene DISC1 is associated with schizophrenia in

  one large family. The DISC1 protein normally regulates trafficking of molecules within neurons, but when researchers inserted the schizophrenia-associated mutant version of DISC1 into mice, they found that the mice developed enlarged lateral ventricles.
• People with schizophrenia differ from controls in the structure and functional activity of the corpus callosum.
• the idea that schizophrenia may reflect underactivation of the frontal lobes

  hypofrontality hypothesis
• In discordant identical twin pairs, where one twin is healthy and one has

  schizophrenia, reduced activity of the frontal cortex is evident only in the affected twin.
• the surgical separation of a portion of the frontal lobes from the rest of the brain, once used as a treatment for schizophrenia and many other ailments

  lobotomy
• an early antipsychotic drug that revolutionized the treatment of schizophrenia that was discovered in the early 1950s; specifically powerfully reduced positive symptoms

  chloropromazine
• difficulty or distortion in voluntary movement


  dyskinesia
• a disorder associated with first-generation antipsychotic use and characterized by involuntary movements, especially of the face and mouth

  tardive dyskinesia
• an exaggerated "rebound" psychosis that may emerge when doses of antipsychotic medication are reduced


  supersensitivity psychosis
• Used for almost any mental disorder, not just schizophrenia, lobotomies were performed on some 40,000 people in the U.S. alone.
• Tardive dyskinesia may arise from the chronic blocking of dopamine receptors, which results in receptor supersensitivity. it frequently takes a long time to develop and tends to be irreversible.
• "neuroleptic" any class of drugs that alleviate symptoms of schizophrenia, typically by blocking dopamine receptors

  antipsychotics