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Chapter 7

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McMaster University
Richard B Day

Psych 2AP3: Abnormal Psychology – Major Disorders Chapter 7: Mood Disorders and Suicide What are Mood Disorders? - Two key moods involved in mood disorders are mania, characterized by intense and unrealistic feelings of excitement and euphoria, and depression, which involves feelings of extraordinary sadness and dejection - Mixed episode cases, person experiences rapidly altering moods such as sadness, euphoria, and irritability all within the same episode of illness - Unipolar disorders: person experiences only depressive episodes - Bipolar disorders: person experiences both manic and depressive episodes - Differentiate among the mood disorders in terms of severity and duration - Major depressive episode: person must be markedly depressed for most of every day and for most days for at least two weeks and at least three or four other symptoms that range from cognitive symptoms, to behavioural symptoms, to physical symptoms - Manic episode: person shows markedly elevated, euphoric, or expansive mood, often interrupted by occasional outburst of intense irritability or even violence, must persist for at least a week with three or more additional symptoms ranging from behavioural symptoms, to mental symptoms, to physical symptoms - The Prevalence of Mood Disorders  15 to 20 times more frequent than schizophrenia and almost the same rate as all the anxiety disorders together  Unipolar major depression is much more common, and its occurrence has apparently increased in recent decades (12% lifetime prevalence Canada, 17% U.S.)  Rates for unipolar depression are higher for women than for men (2:1)  Bipolar disorder lifetime prevalence 0.4-2.2%, and there is no discernible difference in the prevalence rates between the sexes Unipolar Mood Disorder - Depressions that are not mood disorders:  Generally not considered mood disorders except when they are unusually severe and/or prolonged  Loss and the grieving process:  Grief is a psychological process that appears to be more difficult for men than for women  Usually four phases of normal response to the loss of a spouse or close family member: o Numbing and disbelief that may last from a few hours to a week and may be interrupted by outbursts of intense distress, panic, or anger o Yearning and searching for the dead person, which may last fir weeks or months. Typical symptoms include restlessness, insomnia, and preoccupation with the dead person o Disorganization and despair that set in after yearning and searching diminish. This is when the person finally accepts the loss as permanent and tries to establish a new identity. Criteria for MDD may be met during this phase o Some level of reorganization when people gradually begin to rebuild their lives, sadness abates, and zest for life returns  Some people become stuck in the middle of the normal response sequence  Usually not diagnosed for the first two months following the loss  Postpartum “blues”:  Postpartum depression sometimes occurs in new mothers following the birth of a child  Symptoms of postpartum blues include emotional lability, crying easily, and irritability, often liberally intermixed with happy feelings  Occur in 50-70% of women within 10 days of the birth of their child and usually subside on their own  Mild and does not represent a mental disorder  Major depression occurs no more frequently in postpartum depression than would be expected in women of the same age and socioeconomic status who had not given birth  Greater likelihood of developing major depression if the postpartum blues are severe  Hormonal readjustments may play a role in postpartum blues and depression  Postpartum blues or depression may be more likely to occur if the new mother has a lack of social support and/or has difficulty adjusting to her new identity and responsibilities and/or if the woman has a personal or family history of depression that leads to heightened sensitivity to the stress of childbirth - Dysthymic disorder:  Point at which mood disturbance becomes a diagnosable mood disorder is a matter of clinical judgment and usually concerns the degree of impairment in functioning that the individual experiences  Must have a persistently depressed mood most of the day, for more days than not, for at least two years  Periods of normal mood may occur briefly, but they usually last for only a few days to a few weeks  3-6% of Canadian adults develop dysthymia at some point in their lives  Average duration is 5 years but can persist for 20+ years  Chronic stress has been shown to increase the severity of symptoms  Nearly half may relapse within an average of about 2 years  Often begins during the teenage years, and over 50% have an onset before age 21 - Major depressive disorder:  Person exhibit more symptoms than are required for dysthymia and that the symptoms be more persistent  Must experience markedly depressed moods or marked loss of interest in pleasurable activities most of every day, nearly every day, for at least two consecutive weeks  Must experience at least three or four additional symptoms during the same period including cognitive, behavioural physical symptoms  Few occur in the absence of anxiety  Very high levels of comorbidity between mood and anxiety disorders  Depression through the life cycle:  Onset occurs during late adolescence up to middle adulthood  Found major depression in preadolescent children, 2-3% of school-aged children  Anaclitic depression: when infants are separated for a prolonged period from their attachment figure  Incidence of depression rises sharply during adolescence  15-20% of adolescents experience major depressive disorder at some point during their adolescent years, and the average age of onset for adolescent depression has decreased  Occurrence of major depression continues into later life  One-year prevalence is lower in people over age 60 than in younger adults  Depression in later life can be difficult to diagnose because many of the symptoms overlap with those of several medical illnesses and dementia  Specifiers for major depression:  Some individuals who meet the criteria major depression also have additional patterns of symptoms or that are important to note when making a diagnosis because they have implications for understanding more about the course of the disorder and/or its most effective treatment  One such specifier is major depressive episode with melancholic features: in addition to meeting the criteria for major depression, a patient either has lost of interest  Severe major depressive episode with psychotic features: psychotic symptoms may sometimes accompany symptoms of major depression  Major depressive episode with atypical features includes a pattern of symptoms characterized by mood reactivity  Major depression may coexist with dysthymia in some people. A condition given the designation double depression  Depression as a recurrent disorder:  Single or recurrent episodes  Depressive episodes are usually time-limited  Chronic major depressive disorder: when major depression does not remit for over two years  Recurrence has been distinguished from relapse, where the latter term refers to the return of symptoms within a fairly short period of time and probably reflects the fact that the underlying episode of depression has not yet run its course  Proportion of patients who exhibit a recurrence of major depression is about 80%  Probability of recurrence increases with the number of prior episodes  People have residual depressive symptoms even though they no longer meet diagnostic criteria for a major depressive episode  People with residual symptoms or with significant psychological impairment, following an episode are more likely to have recurrences than those whose symptoms remit completely  Seasonal affective disorder:  Must have had at least two episodes of depression in the past two years occurring at the same time of the year, and full remission must have occurred at the same time of the year  Cannot have had other, nonseasonal depressive episodes in the same two-year period, and most of the person’s lifetime depressive episodes must have been of the seasonal variety Causal Factors in Unipolar Mood Disorder - Biological causal factors:  Genetic influence:  Family studies have shown that the prevalence of mood disorder is three times higher  Twins studies also suggest a moderate genetic contribution  MZ twins are twice as likely to develop major depression than DZ twins  31-42% of the variance in major depression due to genetic influence  More variability due to nonshared environmental influences  Early onset, severe, and recurrent forms appear to have a higher heritability  Dysthymic disorder may be less influenced by genetic factors  Adoption study found that unipolar depression occurred seven times more often in biological relatives  Serotonin-transporter gene, involved in the transmission and reuptake of serotonin, have two short alleles might predispose to depression  Gene-environment interaction: individuals who possessed ss alleles were twice as likely to develop depression following stressful life events than those who possessed the ll allele  Those who had ss alleles and had had severe maltreatment as children were twice as likely to develop depression  Neurochemical factors:  Norepinephrine, dopamine, and serotonin: antidepressant medications seemed to have the effect of increasing their availability  Monoamine hypothesis: depression was at least sometimes due to an absolute or relative depletion of one or all of these neurotransmitters at important receptor sites in the brain  Impaired synthesis of neurotransmitters in presynaptic neuron  Increased degradation of neurotransmitters once released  Altered functioning of postsynaptic receptors  Neurotransmitters known to be involved in the regulation of behavioural activity, emotional expression, and vegetative function  Some studies have found the opposite of what is predicted by the monoamine hypothesis  Lowered serotonin activity in patients with high levels of suicidal ideation  Long-term effects of antidepressants do not emerge until two to four weeks later, when neurotransmitter levels may have normalized  Neurotransmitters and their interaction with other disturbed hormonal and neurophysiological patterns and biological rhythms  Interaction between different neurobiological systems can promote resilience to major stress  Abnormalities of hormonal regulatory systems:  Human stress response associated with elevated activity of the HPA axis, which is partly controlled by norepinephrine and serotonin  Perception of threat can cause the release of CRH which triggers the release of ACTH, which triggers the release of cortisol  Blood plasma cortisol levels elevated in 20-40% of depressed outpatients and 60-80% of severely depressed hospitalized patients  Sustained elevations in cortisol can result from increased CRH activation, increased secretion of ACTH, or the failure of feedback mechanisms  45% of seriously depressed patients: suppressor of plasma cortisol fails to entirely supress cortisol  Depressed patients with elevated cortisol also tend to show memory impairment and problems with abstract thinking and problem solving  Prolonged elevations in cortisol result in cell death in the hippocampus  Stress in infancy can promote long-term changes increasing the activity of the HPA axis  Hypothalamic-pituitary-thyroid axis: 20-30% of depressed patients show dysregulation of the axis  May show improvement when administered thyrotropin- releasing hormone  Neurophysiological and neuroanatomical influences:  Damage to the left anterior or prefrontal cortex often leads to depression  Depression in people without brain damage may be linked to lower levels of brain activity in the same region  EEG activity in both cerebral hemispheres in depressed patients shows imbalance in EEG activity of the two sides of the prefrontal regions of the brain  Patients in remission show the same pattern as do children at risk for depression  Lower activity on the left prefrontal cortex is thought to be related to symptoms of reduced positive affect and approach behaviours to rewarding stimuli, and increased right-sided activity is thought to underlie increased anxiety symptoms  Anterior cingulate cortex shows abnormally low levels of activation in depressed patients  Orbitofrontal cortex show decreased volume  Chronic depression is associated with smaller hippocampal volume, which could be due to cell atrophy or cell death  Amygdala tends to show increased activation  Sleep and other biological rhythms:  Sleep: o Depressed patients show a variety of sleep problems: early morning awakening, periodic awakening and difficulty falling asleep (80% hospitalized, 50% out) o EEG recording show first period of REM sleep after only 60 minutes or less of sleep and greater amounts of REM sleep early in the night o Intensity and frequency of REM greater than non- depressed patients resulting in a lower amount of deep sleep  Circadian rhythms: o Include body temperature, propensity to REM sleep, secretion of cortisol, thyroid-stimulating hormone and growth hormone o Controlled by two related central oscillators o Abnormalities in rhythms in depressed patients o Two current theories are: that the size and magnitude of the circadian rhythms is blunted, and that the various circadian rhythms that are normally well synchronized with each other become desynchronized  Sunlight and seasons: o Seasonal affective disorder: patients seem to be responsive to the total quantity of available light in the environment o Many seasonal variations in basic functions such as sleep, activity, and appetite are related to the amount of light in a day o Patients who fit the seasonal pattern usually show increased appetite and hypersomnia, disturbances in their circadian cycles o Serotonin may be dysregulated in people with seasonal affective disorder - Psychosocial causal factors:  Stressful life events:  Stressors may interact with one another to increase the person’s risk of depression  Independent life events vs. dependent life events  Depressed people who have experienced a stressful life event tend to show more severe depressive symptoms  70% of people with a first onset have had a recent major stressful life event, 40% of people with recurrent episode have had a recent major life event  Mildly stressful events and chronic stress: o Studies applying the more sophisticated strategies for assessing life stress have not found minor stressful events to be associated with the onset of clinical depression o Minor events may play more of a role in the onset of recurrent episodes than the initial episode o Several studies have associated chronic stress with increased risk for the onset and maintenance of MD  Individual differences in responses to stressors – vulnerability and invulnerability factors: o Women at genetic risk for depression are three times more likely to experience more stressful life events and are more sensitive to them o Gene-environment interaction mediated by the presence of two short alleles of the serotonin- transporter gene o Individuals with two short alleles were twice as likely to develop depression following major stressful life events o Among women who experienced a severe event, 4 factors were associated with not becoming depressed: having an intimate relationship with a spouse, having no more than three children still at home, having a job outside the home, and having a serious religious commitment o Depression is more prevalent among people who live alone  Different types of vulnerabilities for unipolar depression:  Personality and cognitive diatheses: o Neuroticism is the primary personality variable that serves a vulnerability factor for depression and stressful life events o Neuroticism is associated with a worse prognosis o High levels of introversion o Negative patterns of thinking that make people prone to depression more likely to become depressed when face with stressful life events  Early adversity and parental loss as a diathesis: o Incidence of depression three times higher in women who had lost heir mother before the age of 11
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