Answers to Concept Checks

• 7.1
  1. Whereas the biomedical model considers only the physical, pathological mechanisms that underlie mental illness, the biopsychosocial model considers the contributions of these biological factors along with psychology (thoughts, emotions, or behaviors) and social situation (environment, social class, discrimination, or stigmatization).
  2. The following disorders occur in greater than 2 percent of the United States population per year: specific phobia, social anxiety disorder, major depressive disorder, alcohol use disorder, posttraumatic stress disorder, generalized anxiety disorder, panic disorder, and bipolar disorder
• 7.2
  1. Positive symptoms of schizophrenia including delusions, hallucinations (usually auditory), disorganized thought, and disorganized behavior are likely to improve from treatment with an antipsychotic medication. Negative symptoms including disturbance of affect and avolition are largely unaffected by antipsychotic medications.
  2. Major depressive episodes include a two-week duration of at least five of the following symptoms: depressed mood, loss of interest (anhedonia), sleep disturbance, feelings of guilt, lack of energy, difficulty concentrating, changes in appetite, psychomotor symptoms, and suicidal thoughts. At least one of the symptoms must be depressed mood or anhedonia. Manic episodes include a one-week duration of at least three of the following symptoms: elevated or expansive mood, distractibility, decreased need for sleep, grandiosity, flight of ideas or racing thoughts, agitation, pressured speech, and engagement in risky behavior.
  3. Major depressive disorder contains at least one major depressive episode with no manic episodes. Bipolar I disorder has at least one manic episode with or without depressive episodes. Bipolar II disorder has at least one hypomanic episode with at least one major depressive episode. Cyclothymic disorder has hypomanic episodes and dysthymia that is not severe enough to be a major depressive episode.
  4. Obsessions are persistent, intrusive thoughts and impulses that produce tension. In this case, the obsession is the patient's thought that someone will break into her apartment. Compulsions are repetitive tasks that relieve tension but cause significant impairment in a person’s life. This patient's compulsion is that she must check the latch on her apartment door five times before going to bed. Their relationship is that obsessions raise tension while compulsions relieve that tension.
     
     

  5. Cluster	Features	Personality Disorders
     A	Odd or eccentric	Paranoid, schizotypal, schizoid
     B	Dramatic, emotional, or erratic	Antisocial, borderline, histrionic, narcissistic
     C	Anxious or fearful	Avoidant, dependent, obsessive–compulsive

• 7.3
  1. In depression, levels of cortisol are increased. Many neurotransmitter levels are reduced, including norepinephrine, serotonin, and dopamine.
  2. Mutations in the presenilin genes (chromosomes 1 and 14) and β-amyloid precursor protein gene (chromosome 21) are associated with increased risk for Alzheimer’s disease.
  3. Dopamine levels are elevated in schizophrenia and reduced in Parkinson’s disease. Thus, treatments for one disorder may cause symptoms similar to those of the other.