Chapter 15 Psychological Disorders

1. Chapter 15Psychological Disorders

2. Mood Disorders • Mental illness results from the combination of biological predisposition and experiences. • Both play an important role. • A solid understanding of both aspects is necessary for successful treatment.

3. Mood Disorders • Major depression - feeling sad and helpless everyday for weeks and includes the following characteristics (DSM-IV): • Little energy. • Feelings of worthlessness. • Suicidal thoughts. • Feelings of hopelessness. • Difficulty sleeping. • Difficulty concentrating. • Little pleasure

5. Mood Disorders • Similar symptoms can result from hormonal problems, head injuries, brain tumors, substance abuse, or other illnesses. • Absence of happiness is more reliable symptom than increased sadness. • Occurs at any age, but uncommon in children • Twice as common in women • 10% lifetime prevalence.

6. Mood Disorders • Studies of twins and adopted children suggest a moderate degree of heritability. • Some of the genes associated with depression are also associated with anxiety disorders, ADD, OCD, substance-abuse disorders, bulimia, migraine headaches, irritable bowel syndrome, and several other conditions. • Risk is elevated among relatives of women with early-onset depression (before 30).

7. Mood Disorders • Predisposition depends on a variety of genes. • Effects of these genes have varied between studies

8. Mood Disorders • One gene identified controls the serotonin transporter protein. • controls the ability of the axon to reabsorb the neurotransmitter after its release. • Two “short forms” of the gene are associated with an increased likelihood of depression after stressful events. • May alters people’s reactions to stressful events or make them more sensitive to environmental influences

10. Mood Disorders • A few cases of depression are linked to viral infections. • Borna disease is a viral infection which may predispose people to depression • Illustrates that many different causes can lead to similar behavioral results

12. Mood Disorders • Postpartum depression is depression after giving birth. • Affects about 20% of women and most recover quickly • More common among women who have suffered depression at other times. • May be associated with a drop in estradiol and progesterone levels. • Testosterone drop in men also associated with increased probability

13. Mood Disorders • Depression is also associated with the following brain activity: • Decreased activity in the left prefrontal cortex. • Increased activity in the right prefrontal cortex.

14. Mood Disorders • Many drugs used to treat psychiatric disorders discovered by accident • Categories of antidepressant drugs include: • Tricyclics. • Selective serotonin reuptake inhibitors. • MAOI’s. • Atypical antidepressants.

16. Mood Disorders • Tricylclics - operate by blocking transporter proteins that reabsorb serotonin, dopamine, and norepinephrine into the presynaptic neuron after release. • Examples: imipramine (Tofranil) • Also block histamine receptors, acetylcholine receptors, and certain sodium channels. • Creates side-effects (dry mouth, difficulty urinating, heart irregularities)

17. Mood Disorders • Selective serotonin reuptake inhibitors (SSRIs) - works by blocking the reuptake of the neurotransmitter serotonin. • Examples: Fluoxetine (Prozac), setraline (Zoloft), fluvoxamine (Luvox), citalopram (Celexa) and paroxetine (Paxil). • Work in a similar fashion to tricyclics but are specific to the neurotransmitter serotonin. • Milder side effects but same effectiveness

18. Mood Disorders • Monoamine oxidase inhibitors (MAOI’s) - blocks the enzyme monoamine oxidase that metabolizes catecholimines and serotonin into inactive forms. • Blockage of the enzyme results in more of the transmitters in the presynaptic terminal available for release. • Usually prescribed if SSRI’s and tricyclics are not effective.

19. Mood Disorders • Atypical antidepressants - a miscellaneous group of drugs with antidepressant effects and mild side effects. • Example: bupropion (Wellbutrin) • Works by inhibiting the reuptake of dopamine and to some extent, norepinephrine but not serotonin.

21. Mood Disorders • St. Johns’ wort is an herb that is often used as a treatment for depression by many. • Marketed as a nutritional supplement and not regulated by the FDA. • Believed to work in the same way as SSRI’s but effectiveness is controversial. • Increases the effectiveness of a liver enzyme that can decrease the effectiveness of other medications.

22. Mood Disorders • Studies indicate half of people show a good response within weeks after use of antidepressant drugs • About same percentage respond to therapy • 30% respond to a placebo • Combination of both benefits only a slightly higher percentage • Little difference regarding the various types of antidepressant drug

24. Mood Disorders • Benefits of antidepressant is greatest for people with severe depression. • Antidepressants are generally ineffective for people who suffered abuse, neglect, or other trauma during early childhood. • Usually respond better to psychotherapy • Use of antidepressants in children controversial • Most studies found ineffective and can sometimes increase suicidal thoughts

26. Mood Disorders • Exactly how antidepressant drugs work is unclear. • Antidepressant alter synaptic activity quickly but the effects on behavior are not derived until weeks later. • Reveals depression is not directly and solely the result of low serotonin levels. • Blood samples show normal levels of serotonin turnover in depressed people.

27. Mood Disorders • In some depressed people, neurons in the hippocampus and the cerebral cortex shrink. • Behavioral effects of antidepressant drugs often take longer than the effect on our neurochemisrty which happen within hours • One explanation is that antidepressant drugs increases the release of BDNF which promotes neuron growth and survival.

28. Mood Disorders • Electroconvulsive therapy (ECT) is an electrically induced seizure that is used for the treatment of severe depression. • Used with patients who have not responded to antidepressant medication or are suicidal. • Applied every other day for a period of two weeks. • Side effects include memory loss. • Memory loss can be minimized if shock is localized to the right hemisphere.

30. Mood Disorders • A drawback of ECT is the high risk of relapse. • Usually accompanied with drug treatment, psychotherapy and periodic ECT after initial treatment. • How exactly ECT relieves depression is unknown. • altering of the expression of genes in the hippocampus and frontal cortex is suggested.

31. Mood Disorders • “Receptive transcranial magnetic stimulation” is another treatment for depression in which an intense magnetic field is applied to the scalp, to stimulate the neurons. • Like ECT in its level of effectiveness. • Exact mechanisms of its effects are also unknown.

32. Mood Disorders • Disruption of sleep patterns is common in depression. • Typically fall asleep but awaken early and are unable to get back to sleep. • Enter REM sleep within 45 minutes and have an increased average number of eye movements during REM sleep. • Sleep pattern disruption also increases the likelihood of depression and is a lifelong trait of people that are depressed.

34. Mood Disorders • A night of total sleep deprivation is the quickest method of relieving depression. • Increases proliferation of new neurons in the hippocampus • Half become depressed again after the next night’s sleep. • Extended benefits derived from altering sleep schedule on subsequent days and combining sleep alteration with drug therapies • Exact mechanism are not unknown.

35. Mood Disorders • Hormone leptin has shown some promise as an alternative treatment. • Regular exercise is also effective. • Increases blood flow to the brain. • Reduces the effects of stress. • Can be combined with other treatments to magnify benefits.

36. Mood Disorders • Unipolar disorder is characterized by an alternating states of normality and depression. • Bipolar disorder (manic-depressive disorder) is characterized by the alternating states of depression and mania. • Mania - restless activity, excitement, laughter, self-confidence, rambling speech, and loss of inhibition.

37. Mood Disorders • Bipolar disorder I -characterized by full blown episodes of mania. • Bipolar disorder II - characterized by much milder manic phases, called hypomania, of which anxiety and agitation are the primary symptoms. • Each approximately 1% of people. • Average age of onset is in the early 20’s. • Brain’s use of glucose increases during periods of mania and decreases during periods of depression.

39. Mood Disorders • Research suggests a heritability basis for bipolar disorder (Craddock & Jones, 1999). • Twin studies suggest monozygotic twins share a 50% concordance rate. • Dizygotic twins, brothers, sisters or children share a concordance rate of 5-10%. • Comparison of chromosomes have identified several genes that are somewhat more common in people with the disorder. • Genes simply increase the risk but do not cause the disorder.

40. Mood Disorders • Treatments for bipolar include: • Lithium - a salt that stabilizes mood and prevents relapse in mania or depression • Drugs - anticonvulsant drugs such as valproate (depakote) and carbamazepine • Drugs work by: • decreasing glutamate activity • blocking the synthesis of the brain chemical arachidonic acid, which is produced during brain inflammation.

41. Mood Disorders • Seasonal affective disorder (SAD) is a form of depression that regularly occurs during a particular season. • Patients with SAD have phase-delayed sleep and temperature rhythms; most depressed people have phase-advanced patterns. • Treatment often includes the use of very bright lights. • Most likely explanation is that the light affects serotonin synapses and alters circadian rhythms.

43. Schizophrenia • Schizophrenia is a disorder characterized by deteriorating ability to function in every day life and some combination of the following: • Hallucinations • Delusions • Thought disorder • Movement disorder • Inappropriate emotional expression • (DSM-IV)

44. Schizophrenia • Causes are not well understood but include a large biological component. • Symptoms of the disorder can vary greatly. • Can be either acute or chronic: • Acute - condition has a sudden onset and good prospect for recovery. • Chronic - condition has a gradual onset and a long-term course.

45. Schizophrenia • Positive symptoms are behaviors that are present that should be absent • Two cluster of positive symptoms of schizophrenia include: • Psychotic • Disorganized

46. Schizophrenia • Psychotic - consists of delusions and hallucinations. • Delusions: unfounded beliefs • Hallucinations: abnormal sensory experiences associated with increased activity in the thalamus, hippocampus and cortex • Disorganized - inappropriate emotional displays, bizarre behaviors and thought disorders(difficulty using and understanding abstract concepts).

47. Schizophrenia • Negative symptoms are behaviors that are absent that should be present. • Weak social interaction. • Emotional expression. • Speech. • Working memory. • Negative symptoms are usually stable over time and difficult to treat.

48. Schizophrenia • Schizophrenia affects about 1% of the population and range in severity. • Occurs in all parts of the world, but is 10 to 100 times more common in the United States and Europe than in third-world countries. • More common in men than in women by a ratio of about 7 to 5. • More severe and earlier age of onset for men (early 20’s versus late 20). • May be related to release of dopamine

49. Schizophrenia • Twin studies suggest a genetic component, but does not depend on a single gene. • Monozygotic twins have a much higher concordance rate (agreement) than dizygotic twins. • But monozygotic twins only have a 50% concordance rate. • Other factors may explain the difference. • Greater similarity between dizygotic twins than siblings suggests a prenatal/postnatal environmental effect.