Textbook pgs 561 - 569
Environmental Influences on MDD:
As with schizophrenia, prenatal events contribute to MDD. Mothers who were in their third trimester of pregnancy during a famine known as the "Dutch Hunger Winter" of 1944-1945 not only gave birth to more offspring with schizophrenia but were also more likely to give birth to individuals with MDD Stress often serves as a trigger for depressive episodes
stress and cortisol in MDD
Because cortisol levels increase in response to stress, this system provides a link between stressful life events, circadian disruption, and the development of depression. It is possible that repeated stress and the associated release of cortisol and other glucocorticoids change the responses of the dopaminergic reward pathways originating in the midbrain
biochemistry of bipolar disorder
Bipolar disorder is related to oxidative stress, or an imbalance between the production of free radicals and the body's defenses against them In particular, bipolar disorder causes oxidative damage to the DNA of brain cells, which in turn leads to apoptosis
lithium
A simple salt that appears to stabilize serotonin and norepinephrine levels in cases of bipolar disorder. produce antioxidant effects in animal models of mania and are likely to produce relief from symptoms in humans through this same means.
electroconvulsive therapy (ECT)
A treatment for depression in which convulsions are produced by the passage of an electric current through the brain. Electroconvulsive therapy (ECT) produces significant relief for depressed patients who do not respond to medication or CBT
selective serotonin reuptake inhibitors (SSRI)
A type of medication, used to treat major depressive disorder and related conditions, that interferes with the reuptake of serotonin at the synapse.
bipolar disorder
A disorder featuring at least one lifetime episode of mania, which is often preceded or followed by a period of depression.
major depressive disorder (MDD)
A disorder in which intense feelings of sadness, hopelessness, and worthlessness persist a minimum of two weeks.
MDD risk factors
A number of mood disturbances appear to be either caused or made worse by changes in female hormones, including premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD),postpartum depression, and mood disturbances experienced by women undergoing menopause
biochemistry of MDD
Abnormalities in monoamine activity, and serotonin activity in particular, are associated with depression.
mania
An unrealistically elevated, expansive, or irritable mood accompanied by unusually high levels of goal-directed behavior or energy that lasts about one week.
Genetic Contributions to MDD:
Genes play a moderate role in the development of MDD. Based on analyses of twins, the heritability of depression appears to be around 40 percent Candidate genes for depression are involved with serotonin reuptake and genes that regulate the circadian rhythm
__________ amounts of DNA damage is correlated with the number of lifetime manic episodes experienced by patients.
Higher
electroconvulsive therapy (ECT) treatment
In ECT, the patient is anesthetized and given a muscle relaxant while seizures are induced by electricity applied through electrodes on the head. Six to 12 treatments are given, typically at a rate of three per week
decision making tasks + MDD
During decision-making tasks, patients with MDD showed abnormal activation in the anterior cingulate cortex (ACC) relative to healthy controls, suggesting that these patients work harder to complete cognitive tasks
bipolar disorder greater risk in actors and artists:
Kay Jamison ( 1993) argues that artists are at greater risk for bipolar disorder than other people, Many noted actors and actresses have been formally diagnosed with bipolar disorder. A controlled study comparing patients with bipolar disorder, patients with major depressive disorder, and healthy controls participating in creative or non creative disciplines supports these observations. The patients with bipolar disorder scored similarly on tests of creativity to the healthy controls in creative disciplines and higher than either those with major depressive disorder or controls in non creative disciplines
altered norepinephrine function is associated with ---
MDD
there is a biological basis for
MDD
MDD rates
MDD affects approximately 7 percent of the adult population each year Rates of MDD drop with age, with people in the 18-29-year-old age group having rates that are three times higher than people over 60 years old. Prior to adolescence, rates of MDD for boys and girls are approximately equal. However, rates for boys and girls begin to diverge between ages 13 and 15
dopamine in MDD
Patients diagnosed with MDD have lower levels of a major byproduct of dopamine, which suggests that dopamine activity is also reduced in this disorder. The extent of binding of dopamine to the D2 receptors in the striatum, which includes the nucleus accumbens, distinguishes between patients who respond well to SSRis and those who do not
brain and MDD
Reduced volumes in the hippocampus and the orbitofrontal cortex have been observed in the brains of patients with MDD
problems with SSRIs
SSRis have significant side effects and only about 30-35 percent of patients with MDD treated with SSRis experience complete remission, leading to the need for alternate or complementary therapies
medications for bipolar disorder
SSRis, benzodiazepines (e.g., Valium), antipsychotics, and anticonvulsant mood stabilizers. lithium
SSRIs function in depression
Selective serotonin reuptake inhibitors (SSRis), frequently used to treat depression, act to increase the availability of serotonin at the synapse.
bipolar disorder and schizophrenia --- similarities
Similar brain structure abnormalities, including reduced gray matter density and cortical thickness, are observed in both schizophrenia and bipolar disorder Both conditions are associated with smaller white matter volume, a thinner parahippocampus, a thinner right orbitofrontal cortex, and thicker temporoparietal and left superior motor cortices
faster aging in bipolar disorder
Similar changes in inflammation, amyloid, and neurotrophin activity are observed in both patients with bipolar disorder and individuals with dementia Individuals with bipolar disorder experience earlier onset and higher rates of many diseases, including cardiovascular disease, cancer, and autoimmune diseases
is ECT safe?
Some patients undergoing the procedure have experienced associated memory problems but the procedure is considered safe There is no evidence that the procedure produces permanent brain damage
stages of sleep + MDD
Some people who are depressed enter their first cycle of REM sleep after approximately 45 minutes of sleep rather than the normal 90 minutes. Stages 3 and 4 ofNREM sleep are reduced, and the lighter stages 1 and 2 are more prominent. Because it is much easier to awaken during REM or during NREM stages 1 and 2, frequent waking during the night is a common complaint associated with depression.
Stader and Hokanson (1998) study -- conclusion
Stress might lead to depression by leading to a larger and prolonged release of cortisol particularly in people with short versions of the serotonin transporter gene cortisol regulation appears to be impaired in some people with MDD.
treatment for MDD
The most common treatment for MDD is antidepressant medication, particularly an SSRI. antidepressants, exercise and cognitive behavioral therapy are also a treatment for MDD as well as ECT and deep brain stimulation A combination of antidepressants and cognitive behavioral therapy typically produces the best long - term outcomes for patients with depression
Women are ___________ likely to be diagnosed with bipolar disorder than men
more
Children and youth under the age of 18 with symptoms of bipolar disorder are diagnosed with -----
disruptive mood dysregulation disorder instead
bipolar disorder and schizophrenia --- difference
bipolar disorder has a larger than normal intracranial volume which is a measure of all tissue and fluid within the skull which schizophrenia doesn't have
People who die as a result of suicide show abnormal density and sensitivity of ________________ receptors in the prefrontal cortex
norepinephrine
Genetics and Bipolar Disorder:
candidate genes for bipolar disorder and schizophrenia overlap significantly.
In addition to its other duties, serotonin acts as---
a neurotrophic factor that stimulates both neurogenesis and the release of brain-derived neurotrophic factor (BDNF)
MDD is associated with reduced axonal density in neurons releasing norepinephrine, a state that is reversed by the use of _______________
antidepressants
Stader and Hokanson (1998) study
asked participants to list daily stressors, such as having an argument with a friend. These self-reports were then correlated with the participants' moods. Depressive episodes were often preceded by significant stressors.
Effective antidepressant medications share the ability to stimulate neurogenesis in the ________________
hippocampus
In addition, like antidepressant medications, ECT appears to stimulate neurogenesis in the __________________
hippocampus
Lithium salts also promote adult neurogenesis in the _______________
hippocampus
symptoms of MDD
people with major depressive disorder (MDD) often withdraw from activities they previously found rewarding, including hobbies and sex. Major depressive disorder also affects eating habits, energy levels, sleep, and cognition. People report difficulty concentrating and often experience thoughts of hopelessness, guilt, worthlessness, and suicide.
The DSM-5 definition of MDD
periods of pervasive sadness that last for at least two weeks
Bipolar disorder has been linked to enhanced ____________.
creativity
Further symptoms of bipolar disorder include ---
inflated self-esteem, decreased need for sleep, higher-than-normal verbal output, flight of ideas, distractibility, increased goal-directed activity, and excessive involvement in activities that have a high potential for negative consequences (such as buying sprees or risky sexual encounters).
Lower levels of serotonin activity linked with MDD might result in ________ neurogenesis.
less
People who commit suicide have ___________ concentrations of serotonin and it's by products in the brain and in the cerebrospinal fluid
lower
People who used violent means to commit suicide had lower concentrations of serotonin in the _____________ cortex than those who used less violent means to commit suicide.
prefrontal
Genetic influence on bipolar disorder seem to be ____________ than on MDD
stronger
short version of serotonin transporter gene
those with 1 or 2 copies of the short form of the serotonin transporter gene and who experienced stressful life events were more likely to develop depression than those with 2 copies of the long form
problem with lithium
toxicity and unpleasant side effects
true or false adult women are nearly twice as likely as men to be diagnosed with MDD
true
is deep brain stimulation effective in treating MDD?
yes In one study, the majority of patients achieved remission of their depressive symptoms after two years of stimulation Considering that these patients had been non responders to more conventional treatment, this improvement is impressive.
Increased ____________ activity can also be helpful in combating MDD
aerobic
The average age of onset for bipolar disorder is _______ years
25
Diet May Influence the Prevalence of Bipolar Disorder :
Nations with heavy seafood consumption, such as Iceland, have lower rates of bipolar disorder than nations where seafood consumption is less typical, such as Switzerland and Hungary. Omega-3 fatty acids have been suggested as a possible protective factor, but further research is needed to confirm a causal relationship.
deep brain stimulation
Stimulating electrodes are surgically implanted in the white matter of the cingulate cortex of both hemispheres, and stimulation is delivered constantly.
reserpine
The drug reserpine interferes with the storage of monoamines in vesicles, reducing the amount of these neurochemicals available for release. Although reserpine has been used for centuries in Indian folk medicine to treat heart disease, it is rarely used today due to its ability to produce profound depression
________________ antibodies are more prevalent in people with MDD than in healthy controls
Antiserotonin
depression + sleep
Both sleeping more than normal (more than nine hours) and sleeping less than normal (less than seven hours) are symptoms of depression. Depression might result from irregular or missing circadian rhythms
dexamethasone suppression test (DST) on MDD
Glucocorticoid metabolism is assessed by the dexamethasone suppression test (DST). When dexamethasone is injected into healthy participants, cortisol secretion is suppressed. When the test is administered to adults diagnosed with MDD, about 75 percent fail to show normal cortisol suppression Following successful treatment, these patients respond normally to the DST.
______________ imbalances contribute to both MDD and bipolar disorder
Monoamine
When people are awakened each time they enter ________ sleep, they report a significant reduction in depression
REM
