Mood Disorders
Introduction to Mood Disorders
learning objective : describe the characteristic symptoms of mood disorders (major depression, dysthymia, bipolar disorder) and differentiate the mood disorders from each other and be able to differentiate among different causes of mood disorders
mood : the positive or negative feelings that are in the background of our everyday experiences
when we are in a good mood our thought processes open up, and we are more likely to approach others
mood (or affective) disorders : psychological disorders in which the person’s mood negatively influences their physical, perceptual, social, and cognitive processes.
people who suffer from mood disorders tend to experience intense moods
10% of the U.S population suffers from a mood disorder in a given year
the most common symptom of mood disorders is a negative mood or depression
recurrence of depressive episodes is fairly common and is greatest for those who first experience depression before the age of 15 years
twice as many women suffer from depression than men
this gender difference is consistent across many countries and cannot be explained
rates of depression have been increasing over the past few years
the experience of depression has a variety of negative effects on our behaviors, such as :
loss of interest
loss of productivity
lack of social contact
sense of hopelessness
sadness
may commit suicide
changes in appetite; weight loss or gain
difficulty concentrating, remembering details, and making decisions
fatigue and decreased energy
pessimistic
increased use of alcohol or drugs
irritability, restlessness
loss of interest in personal appearance
persistent aches or pains, headaches, cramps, or digestive problems that do not improve with treatment
sleep disorders; either trouble sleeping or excessive sleeping
thoughts of suicide or attempts of suicide
suicide is the 11th leading cause of death in the United States
a suicide occurs approximately every 16 minutes
almost all the people who die by suicide have a diagnosable psychiatric disorder at the time of their death
Dysthmia and Major Depressive Disorder
learning objectives : describe the characteristic symptoms of mood disorders (major depression, dysthymia, bipolar disorder) and differentiate the mood disorders from each other
people who experience depression for many years, such that it becomes to seem normal and part of their everyday life, and who feel that they are rarely or never happy, will likely be diagnosed with a mood disorder
persistent depressive disorder (dysthymia) : a condition characterized by mild, but chronic, depressive symptoms that last for at least 2 years in adults and at least one year for children and adolescents
it the depression continues and becomes even more severe, the diagnosis may become that of major depressive disorder
major depressive disorder (clinical depression ) : a mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem and by loss of interest or pleasure in normally enjoyable activities
a depressive episode lasts for at least two weeks or longer
those who suffer from major depressive disorder feel intense sadness, despair, and loss of interest in pursuits that once gave them pleasure. these negative feelings profoundly limit the individuals day to day functioning and ability to maintain and develop interests in life.
21 million American adults suffer from a major depressive disorder in any given year
major depressive disorder occurs about twice as often in women as it does in men
in some cases clinically depressed people lose contact with reality and may receive a diagnosis of major depressive episode with psychotic features. in these cases the depression includes delusions and hallucinations
In summary : major depression is a disorder characterized by severe low mood and lack of interest in normally pleasurable activities. these symptoms often involve significant impact on the person’s functioning
In summary : dysthymia is a disorder characterized by mild low mood that is chronic and lasts at least 2 years
Bipolar Disorder
learning objective : describe the characteristic symptoms of mood disorders (major depression, dysthymia, bipolar disorder) and differentiate the mood disorders from each other
bipolar disorder : psychological disorder characterized by swings in mood from overly “high” to sad and hopeless, and back again, with periods of near-normal mood in between
experiences with depression are followed by a more normal period and then a period of mania or euphoria in which the person feels particularly awake, alive, excited, and involved in everyday activities but is also impulsive,agitated, and distracted
bipolar disorder is an often chronic and lifelong disorder that may begin in childhood
in some cases the person may experience both highs and lows at the some time
determining whether a person has bipolar disorder is difficult due to the frequent presence of comorbidity with both depression and anxiety disorders
bipolar is more likely to be diagnosed when it is initially observed at an early age, w hen the frequency of depressive episodes is high, and when there is a sudden onset of the symptoms
in summary : bipolar disorder is characterized by episodes of mania, which include symptoms of impulsivity and agitation
Explaining Mood Disorders
learning objective : differentiate among different causes of mood disorders
mood disorders are known to be in part genetic because they are heritable
serotonin, dopamine, and norepinephrine are known to influence mood, and drugs that influence the actions of these chemicals are often used to treat mood disorders
Videbech and Ravnkilde found that the hippocampus was smaller in depressed subjects than in normal subjects which could be the result of reduced neurogenesis (the process of generating new neurons) in depressed people
antidepressant drugs may alleviate depression in part by increasing neurogenesis
Research Focus : Using Molecular Genetics to Unravel the Causes of Depression
Avshalom Caspi and colleagues used a longitudinal study to test whether genetic predispositions might lead some people, but not others, to suffer from depression as a result of environmental stress
their research focused on the 5-HTT gene, which is known to be important in the production and use of serotonin
the researched focused on that gene because serotonin is known to be important in depression, and because selective serotonin reuptake inhibitors (SSRI) have been shown to be effective in treating depression
biological situational models suggest that a person’s sensitivity to stressful events depends on their genetic makeup
the researchers expected that people with one type of genetic pattern would show depression following stress to a greater extent than people with a different type of genetic pattern
the research included 1,037 adults from Dunedin, New Zealand
genetic analysis of DNA samples allowed researchers to divide the people into two groups based on the characteristics of their 5-HTT gene
one group had a short version of the gene and the other group did not
the participants complete a test where they indicated the number and severity of stressful life events that they had experienced over the last 5 years
the events included employment, financial, housing, health, and relationship stressors
the dependent measure int he study was the level of depression reported by the participant, as assessed using a structured interview test
as the number of stressful experiences the participants reported increased from 0 to 4, so did depression (for the participants with the short version of the gene)
for the participants who did not have the short version of the gene, increasing stress did not increase depression
for the participants who experienced 4 stressors, 33% of the participants who carried the short version of the gene became depressed
only 17% of the participants who did not have the short version did
an individuals response to environmental stress was influenced by their genetic makeup
mood states are influenced in large part by our cognitions
the goal of cognitive therapy for mood disorder is to attempt to change people’s cognitions to be more positive
Weissman and colleagues found that rates of depression varied greatly among countries
highest rates of depression were in European and american countries
lowest rates of depression were found in Asian countries
these difference are due to discrepancies between individual feelings and cultural expectations about what one should feel
people from European and american cultures report that it is important to experience emotions such as happiness and excitement
Chinese report that it is more important to be stable and calm
because Americans may feel that they are not happy or excited but they are supposed to be, this may increase their depression