Download Depression and Its Causes

Depression and Its Causes
• Major depressive disorder
– Characterized by pervasive low mood, lack of motivation,
low energy, and feelings of worthlessness and guilt that
last for at least two consecutive weeks
– Dysthymia
• Form of depression that is milder than major depressive disorder
but lasts longer
– Increase risk of attempting/committing suicide
Copyright 2012 The McGraw-Hill
Companies, Inc.
Depression and Its Causes
• Combination of brain
chemistry and life
circumstance
– Diathesis-stress
model
• Serotonin gene
• Stressful events
– Abusive environments
– Adverse childhood
experiences
Copyright 2012 The McGraw-Hill
Companies, Inc.
Bipolar Disorder and Its Causes
• Characterized by substantial mood
fluctuations, a cycling between very low and
very high moods
– Manic episode
– Cyclothymia
• Milder but longer-lasting form of bipolar disorder
Copyright 2012 The McGraw-Hill
Companies, Inc.
Bipolar Disorder and Its Causes
• Fetal exposure to alcohol
• Genetic component
– Twin studies indicate a 40-70% concordance rate
• Brain abnormalities
• Neurochemistry
– Low serotonin coupled with high norepinephrine
• Stress and trauma
Copyright 2012 The McGraw-Hill
Companies, Inc.
The Bipolar Brain
Copyright 2012 The McGraw-Hill
Companies, Inc.
Major Symptoms and Behaviors of Mood
Disorders
Copyright 2012 The McGraw-Hill
Companies, Inc.
Schizophrenia
Copyright 2012 The McGraw-Hill
Companies, Inc.
Schizophrenia
• Psychotic Disorders
– Disorders of thought and perception, characterized by the
inability to distinguish between real and imagined
perceptions
• Schizophrenia
– Characterized by significant disturbances in thought and
emotion, specifically problems with perception, including
hallucinations
Copyright 2012 The McGraw-Hill
Companies, Inc.
Major Symptoms of Schizophrenia
• Positive
– Hallucinations
– Delusional thinking
– Disorganized thought and speech
– Poorly integrated perception
Copyright 2012 The McGraw-Hill
Companies, Inc.
Major Symptoms of Schizophrenia
• Negative
–
–
–
–
–
Non-responsiveness
Emotional flatness
Immobility or catatonia
Reduction of speaking
Inability to complete tasks
• More difficult to diagnose than positive symptoms
Copyright 2012 The McGraw-Hill
Companies, Inc.
Major Symptoms of Schizophrenia
• Cognitive
–
–
–
–
–
–
Problems with working memory
Attention
Verbal and visual learning and memory
Reasoning and problem solving
Speed of processing
Disordered speech
• Word salad
• Making up new words
Copyright 2012 The McGraw-Hill
Companies, Inc.
Nature and Nurture Explanations of
Schizophrenia
• There appears to be a strong heritable
component – 80 to 85%
• Abuse and neglect during childhood is
associated with greater risk of diagnosis later
in life
– Can lead to changes in brain development
Copyright 2012 The McGraw-Hill
Companies, Inc.
Nature and Nurture Explanations of
Schizophrenia
• Schizophrenia and
the brain
– Abnormal brain
development before birth
– Dysfunctional prefrontal
cortex
– Difficulties in
communication between
neurons
Copyright 2012 The McGraw-Hill
Companies, Inc.
Nature and Nurture Explanations of
Schizophrenia
• Neurochemistry of schizophrenia
– Dopamine hypothesis
• Glutamate deficiencies
• Crucial in
–
–
–
–
–
Learning
Memory
Neural processing
Brain development
Amplifies certain neural signals
Copyright 2012 The McGraw-Hill
Companies, Inc.
Dissociative Disorders
Copyright 2012 The McGraw-Hill
Companies, Inc.
Dissociative Identity Disorder (DID)
• Dissociative disorders occur when there are splits or
gaps in memory, consciousness, or identity.
• Dissociative Identity Disorder
– Development of at least two distinct personalities, each
with its own memories, thoughts, behaviors, and emotions
– Formerly called multiple personality disorder
Copyright 2012 The McGraw-Hill
Companies, Inc.
Causes of Dissociative Disorders
• Lived through a highly traumatic experience
– Sexual or physical abuse
– Survived a terrible accident or natural disaster in
which one was killed
Copyright 2012 The McGraw-Hill
Companies, Inc.