Transcript Nature vs. Nurture in Depression

Nature vs. Nurture in
Depression
By Tori Lewis, Emma
Montgomery, and Soleil McGhee
Causes of Depression
 It has been believed that depression is caused by an
imbalance of the brains natural chemicals.
 Depression passed down in families through genes.
 Depressive disorder is often associated with changes
in brain structures or brain function.
 Physical changes in the body can trigger depression.
I.e.) heart attack, stroke, Parkinson's disease
 Stress has also been a factor that’s has been an on
set of depression.
 A combination of genetic, psychological, and
environmental factors is often involved in the onset of
depression.
Stress and Depression
 Stress is thought to mobilize the
sympathetic nervous system that
triggers the fight-or-flight response and
many physiological reactions.
Stress and Depression
Cont.
 Factors
 Research in primates show maternal deprivation
stresses young animals and may predispose them to
a lifetime of overreaction to stress
 In a study of Old Order Amish in Pennsylvania, the
rate of depression was extremely low
 Research conducted in working-class neighborhoods
suggests that the combination of life stress and
inadequate social support contributes to women's
greater susceptibility to depressive symptoms.
 Surgeon General concludes: "Something about the
environment thus appears to interact with biology to
cause a disproportionate incidence of depressive
episodes.”
Cognitive Theories
 According to cognitive theories, depression arises
from a subjective feeling of helplessness and
entrapment.
 Critical factor is the interpretation of the stressful
event rather than the actual event, itself
 Adolescent girls suffer from depression in far greater
numbers than boys, possibly because they are more
socially-oriented and more dependent on positive
social relationships.
(PHDCN)
Wangby, M., L.R. Bergman, and D. Magnusson,
“Development
of Adjustment Problems in Girls: What Syndromes
Emerge,” Child Development (1999):
 Although 40 percent of non-depressed girls engaged
in property crimes, 68 percent of girls who were
mildly to moderately depressed did so.
 42 percent of girls who were not depressed engaged
in crimes against other persons, compared with 82
percent of mildly to moderately depressed girls.
 57 percent of mildly to moderately depressed girls
engaged in higher levels of aggressive behavior,
compared with only 13 percent of those who were not
depressed.
Depression and Crime Cont.
 Moderately depressed girls were more likely to
commit property crimes and crimes than girls not
depressed
 preliminary findings suggest mildly to moderately
depressed girls may be at risk of engaging in
antisocial behavior
 Benefit of treatment:
 Undermining the development and maintenance of
antisocial behavior
 reducing depression.
Treatments
 Self-help
 Exercise - triggers the production of endorphins.
These natural opiates are chemically similar to
morphine. They may be produced as natural pain
relievers in response to the shock that the body
receives during exercise.
 Exercise boosts activity in the brain's frontal lobes
and the hippocampus.
 Studies have found that exercise increases levels
of serotonin, dopamine and norepinephrine.
(Associated with mood elevation)
Medicines
 Depressive illness is caused by a decrease of
certain chemicals or neurotransmitters in the
brain that are responsible for mood.
Antidepressants stimulate chemical changes
that increase the levels of these
neurotransmitters. Three main
neurotransmitters associated with mood are
serotonin, norepinephrine and dopamine.
Medicine Examples
 Tricyclic antidepressants (TCAs), Affects the uptake
of all three neurotransmitters associated with mood:
serotonin, norepinephrine and dopamine.
 Monoamine oxidase inhibitors (MAOIs), an older
class of antidepressants, increases levels of all three
neurotransmitters by inhibiting an enzyme
responsible for inactivating them.
 Selective serotonin reuptake inhibitors (SSRIs) delay
the reuptake of one of these neurotransmitters,
serotonin, thus raising levels in the brain. With more
natural levels of serotonin in the brain, mood is
elevated from the depressed state to a more normal
state of mind.
Talking therapies
 Supportive counseling helps ease the pain of
depression, and addresses the feelings of
hopelessness that accompany depression.
 Cognitive therapy changes the pessimistic ideas,
unrealistic expectations, and overly critical selfevaluations that create depression and sustain it.
 Cognitive therapy helps the depressed person
recognize which life problems are critical, and which
are minor.
 Helps people to develop positive life goals, and a
more positive self-assessment.
 Problem solving therapy changes the areas of the
person's life that are creating significant stress, and
contributing to the depression.
Studies (Gerald Haeffel)
 Gerald Haeffel and colleagues at the University of
Notre Dame.
 Investigate depression while taking both genes and
environment into consideration.
 Haeffel studied 177 male adolescents from a Russian
juvenile detention facility. They were given a
depression assessment, a questionnaire designed to
determine their mothers’ parenting style, and tested
for the specific dopamine transporter gene previously
implicated in depression. The results showed that
neither cruel mothering patterns, nor the dopamine
transporter gene alone predicted depression. A
combination of both, however, resulted in a higher
risk for depression and suicidal tendencies.
Studies (Gerald Haeffel)
 This study is groundbreaking because it is the
first to support the theory of a dopamine
transporter gene in depression.
 It also represents a modern understanding of
the interaction of nature and nurture.
 As scientists like Haeffel begin to more
frequently use a combination of genetic and
environmental experimental designs, we will
inevitably gain a much deeper, and more
accurate, understanding of human behavior.
Studies (Teuting - 1981)
 Teuting carried out a study in 1981 to
measure the amount of serotonin and
noradrenaline in urine samples of depressed
and non depressed participants.
 He found empirical support for the biology of
depression.
 Depressed participants had lower levels of
these two neurotransmitters in their urine,
compared to control participants.
Nature Vs. Nurture
 "The outside environment creates a stimulus
and response relationship that defines who
we are.” (The surgeons general report)
 Our mental well-being is dependent on the
brain's neurons and how they connect and
interact with other neurons, but it takes a
push from the outside environment to start
the process