Depressive and Bipolar Disorders
Depression: Low, sad state marked by significant levels of sadness, lack of energy, low self-worth, guilt, or related symptoms
Mania: State or episode of euphoria or frenzied activity in which people may have an exaggerated belief that the world is theirs for the taking
Depressive disorders: A group of disorders marked by unipolar depression
Unipolar depression: Depression without a history of mania
Bipolar disorder: Disorder marked by alternating or intermixed periods of mania and depression
8 percent of U.S. adults experience severe unipolar depression in any given year; 5 percent experience mild forms
20 percent of all adults experience unipolar depression at some time in their lives
Lifetime prevalence: 26 percent of women versus 12 percent of men
The average age of onset is 19 years
The rate of severe depression is twice as high among adults under 65 years of age as among those 65 years and older
Approximately 85 percent of people with unipolar depression recover, some without treatment
Around half will experience another episode later in their lives
For a 2-week period, a person displays an increase in a depressed mood for the majority of each day and/or a decrease in enjoyment or interest across most activities for the majority of each day.
Significant distress or impairment
For the same 2 weeks, a person also experiences at least 3 or 4 of the following symptoms:
Considerable weight change or appetite change
Daily insomnia or hypersomnia
Daily agitation or decrease in motor activity
Daily fatigue or lethargy
Daily feelings of worthlessness or excessive guilt
Daily reduction in concentration or decisiveness
Repeated focus on death or suicide, a suicide plan, or a suicide attempt.
Biological view
Studies of genetic factors and biochemical factors suggest unipolar depression has biological causes
Genetic factors
Family pedigree studies
Twin studies: 38% concordance among MZ twins, 20% in DZ
People who are depressed can have an abnormality of their 5-HTT gene, a gene located on chromosome 17
Gene studies
Biochemical factors
Low activity of two neurotransmitters: serotonin and norepinephrine
In the 1950s, blood pressure medications that lower serotonin/norepinephrine often led to depression
Antidepressant drugs bring about increases in norepinephrine and/or serotonin activity
Now, interactions between serotonin, norepinephrine activity, and other neurotransmitters in the brain are considered
Hormones and HPA pathway
HPA pathways are overly reactive in people with depression
Psychological Views: Psychodynamic view
Freud and Abraham: When some people experience real or symbolic loss (e.g., job loss, breakup, identity)
Introjection: feelings for the loved one, including sadness and anger, directed toward themselves
If dependency needs were improperly met during infancy and early childhood, grief worsens over time, and they develop clinical depression
Object relations theorists: Depression results when people's relationships (especially early ones) leave them feeling unsafe and insecure
General research support: Depression may be triggered by major loss; early losses set the stage for later depression
People whose childhood needs were poorly met are particularly likely to become depressed after experiencing a loss
Early losses and inadequate parenting sometimes lead to depression but may not be typically responsible for the development of the disorder
What causes bipolar disorders?
Biological research and perspectives:
Genetic factors
Many theorists believe that people inherit a biological
predisposition to develop bipolar disorders
Family pedigree studies: MZ twins have a 40% concordance rate,
siblings have a 5-10% likelihood
Bipolar disorders linked to genes on chromosomes 1, 4, 6, 10, 11, 12, 13, 15, 18, 20, 21, and 22 (number of genetic abnormalities probably combine)
Depression: Low, sad state marked by significant levels of sadness, lack of energy, low self-worth, guilt, or related symptoms
Mania: State or episode of euphoria or frenzied activity in which people may have an exaggerated belief that the world is theirs for the taking
Depressive disorders: A group of disorders marked by unipolar depression
Unipolar depression: Depression without a history of mania
Bipolar disorder: Disorder marked by alternating or intermixed periods of mania and depression
8 percent of U.S. adults experience severe unipolar depression in any given year; 5 percent experience mild forms
20 percent of all adults experience unipolar depression at some time in their lives
Lifetime prevalence: 26 percent of women versus 12 percent of men
The average age of onset is 19 years
The rate of severe depression is twice as high among adults under 65 years of age as among those 65 years and older
Approximately 85 percent of people with unipolar depression recover, some without treatment
Around half will experience another episode later in their lives
For a 2-week period, a person displays an increase in a depressed mood for the majority of each day and/or a decrease in enjoyment or interest across most activities for the majority of each day.
Significant distress or impairment
For the same 2 weeks, a person also experiences at least 3 or 4 of the following symptoms:
Considerable weight change or appetite change
Daily insomnia or hypersomnia
Daily agitation or decrease in motor activity
Daily fatigue or lethargy
Daily feelings of worthlessness or excessive guilt
Daily reduction in concentration or decisiveness
Repeated focus on death or suicide, a suicide plan, or a suicide attempt.
Biological view
Studies of genetic factors and biochemical factors suggest unipolar depression has biological causes
Genetic factors
Family pedigree studies
Twin studies: 38% concordance among MZ twins, 20% in DZ
People who are depressed can have an abnormality of their 5-HTT gene, a gene located on chromosome 17
Gene studies
Biochemical factors
Low activity of two neurotransmitters: serotonin and norepinephrine
In the 1950s, blood pressure medications that lower serotonin/norepinephrine often led to depression
Antidepressant drugs bring about increases in norepinephrine and/or serotonin activity
Now, interactions between serotonin, norepinephrine activity, and other neurotransmitters in the brain are considered
Hormones and HPA pathway
HPA pathways are overly reactive in people with depression
Psychological Views: Psychodynamic view
Freud and Abraham: When some people experience real or symbolic loss (e.g., job loss, breakup, identity)
Introjection: feelings for the loved one, including sadness and anger, directed toward themselves
If dependency needs were improperly met during infancy and early childhood, grief worsens over time, and they develop clinical depression
Object relations theorists: Depression results when people's relationships (especially early ones) leave them feeling unsafe and insecure
General research support: Depression may be triggered by major loss; early losses set the stage for later depression
People whose childhood needs were poorly met are particularly likely to become depressed after experiencing a loss
Early losses and inadequate parenting sometimes lead to depression but may not be typically responsible for the development of the disorder
What causes bipolar disorders?
Biological research and perspectives:
Genetic factors
Many theorists believe that people inherit a biological
predisposition to develop bipolar disorders
Family pedigree studies: MZ twins have a 40% concordance rate,
siblings have a 5-10% likelihood
Bipolar disorders linked to genes on chromosomes 1, 4, 6, 10, 11, 12, 13, 15, 18, 20, 21, and 22 (number of genetic abnormalities probably combine)
