Chapter 14 - Psychological Disorders Flashcards
What is major depressive disorder?
Person feels sad and helpless for days at a time. Changes in the synapse at the nucleus accumbens make it less responsive to reward. There is a moderate heritability for depression.
What is the relationship between happiness and activity in the left PFC for normal people?
Normal people have a strong relationship between happiness and increased activity in the left PFC.
What area of the brain do people with depression have decreased activity?
People with depression often have decreased activity in the left PFC.
What are the three types of antidepressant drugs?
Tricyclics, Selective serotonin reuptake inhibitors (SSRI’s) and monoamine oxidase inhibitors (MAOI’s)
How do tricyclics work?
They block proteins that reabsorb serotonin, dopamine and norepinephrine into the presynaptic neuron after their release. Tricyclic drugs block the protein so that it can’t reuptake. The result is to prolong the presence of the neurotransmitters in the synaptic cleft, where they continue to stimulate the postsynaptic cell.
What are the side effects of tricyclics?
Tricyclics also block histamine receptors, acetylcholine receptors and certain sodium channels. Histamine produces drowsiness, acetylcholine leads to dry mouth and difficulty urinating and sodium causes heart irregularities.
How do SSRIs work?
They are similar to tricyclics but they only work on serotonin. They produce similar results as tricyclics but with less side effects. Serotonin norepinephrine reuptake inhibitiors block the reuptake of serotonin and norepinephrine.
How do MAOI’s work?
MAOI’s block monoamine oxidase (MAO) a presynaptic enzyme that metabolises catecholamines and serotonin into inactive forms. When MAOI’s block MAO there is more transmitter available for release at the presynaptic terminal.
What do physicians prescribe patients?
They prescribe tricyclics and SSRI’s before MAOI’s.
What food must people taking MAOI’s avoid?
People taking MAOI’s must avoid foods containing tyramine (cheese and raisin’s). Tyramine and MAOI’s together can cause an increase in BP.
What are the levels of neurotransmitters and neurotrophins in people with depression?
People with depression often have normal or increased levels of neurotransmitters. Most people with depression have decreased levels of neuotrophins.
What role do neurotrophins play in depression?
Neurotrophins aid in the survival and growth and connections of neurons. People with depression have a decreased levels of a neurotrophin called brain-derived neurotropic factor (BDNF) that is important for synaptic plasticity, learning and proliferation of new neurons in the hippocampus.
What neurotrophin is linked to depression?
brain-derived neurotropic factor (BDNF)
What role does the hippocampus play?
People with depression have a smaller hippocampus, impaired learning and reduced production of hippocampal neurons.
What alternatives to drugs are there to treat depression?
CBT - psychotherapy is more likely to prevent relapses than drugs.
Exercise is an effective treatment when used with other methods.
What is the most effective treatment plan for people with depression?
Patients receiving psychotherapy and antidepressants show greater improvement than people receiving only one.
What is ECT?
Electroconvulsive therapy. Causes a person to have a seizure.
How is ECT used in treatment of depression?
ECT relieves depression in many cases. Usually given to patients with severe depression. Applied every second day for 2 weeks. Patients given muscle relaxants or anaesthetics to minimise discomfort. Side effects can include memory impairment.
How is sleep impacted by depression?
People with depression usually struggle to go to sleep and awaken early. They usually enter REM sleep within 45 minutes of going to sleep.
How does sleep deprivation improve symptoms?
Sleep deprivation can relieve symptoms for one day.
How can sleep patterns help with depression?
Altering the sleep schedule (i.e. going to bed earlier and awakening earlier) can have similar effects of sleep deprivation and last for a while.
What is the symptoms of bipolar disorder?
Variation between two poles - depression and mania.
What is mania?
Mania is characterised by restless activity, excitement, laughter and excessive self-confidence, rambling speech and loss of inhibitions. Usually onsets in teens or early 20s.
What is Bipolar I disorder?
Full manic episodes.
What is Bipolar II disorder?
mild or hypomanic episodes.
What are the gender differences with bipolar disorder?
Men are more likely to have severe (bipolar I). Women are more likely to get treatment.
What are treatments of bipolar disorder?
Lithium salts. They stabilise mood, preventing a relapse into mania or depression. Dose must be regulated carefully - a low dose is ineffective. High dose is toxic. Other drugs are valproate and carbamazepine. If ineffective, physicians can combine with antidepressants or antipsychotics.
How does lithium, valproate and carbamazepine work?
They decrease the number of AMPA type glutamate receptors in the hippocampus. Excessive glutamate activity is responsible for some aspects of mania. They also block the synthesis of arachidonic acid - produced during brain inflammation. Effects of arachidonic acid are counteracted by omega-3 fatty acids (found in seafood). consistent sleep patterns also helps.
What is seasonal affective disorder?
SAD is depression that reoccurs during a particular season (i.e. winter) especially near the poles where winter nights are long.
How is sleep impacted by SAD?
People with SAD have phase-delayed sleep and temperature rhythms - they become sleepy and wakeful later than normal.
How can SAD be treated?
By very bright lights.
What evidence suggests two types of depression influenced by different genes?
Relatives of people with early-onset depression have a high risk of depression and many other psychological disorders. Relatives of people with late-onset disorder have a high probability of circulatory problems.
What did Caspi and colleagues report to be the relationship between depression and the gene controlling the serotonin transporter protein?
People with the short form of the gene are more likely than other people to react to stressful experiences by becoming depressed. However, in the absence of stressful experiences, their probability is not increased.
Some people offer to train you to use the right hemisphere of your brain more strongly and allegedly to increase creativity. If they were successful, can you see any disadvantages?
People with predominant right-hemisphere activity and decreased left-hemisphere activity show an increased tendency toward depression.
What are the effects of tricyclic drugs?
They block the reuptake of serotonin and catecholamines. They also block histamine receptors, acetylcholine receptors and certain sodium channels, thereby producing unpleasant side effects.
What are the effects of SSRIs?
SSRIs selectively inhibit the reuptake of serotonin.
What are the effects of MAOIs?
MAOIs block the enzyme MAO, which breaks down catecholamines and serotonin. The result is the increased availability of these transmitters.