Mood Disorders: Depression and Bipolar

Mood Disorders

• Major depression and bipolar disorder are common mood disorders
• Major depression involves intense, sustained sadness and hopelessness

Bipolar Disorder

• Individuals show recurrent patterns of depression and mania
• Mania is characterized by extreme levels of energy and euphoria

Monoamine Neurotransmission

• A reduction is linked to depression, elevated levels associate with mania

Dopamine

• Creates positive feelings associated with reward which motivates activity
• Plays a role in conditions affecting the brain, like Parkinson's and schizophrenia
• Reduced levels can contribute to depression, can be helped with dopamine medications when other treatments fail

Norepinephrine

• Functions as both a neurotransmitter and a hormone, involved in "fight or flight"
• Helps transmit messages between nerve cells
• Too little norepinephrine can cause depression, too much results in mania

Serotonin

• Known as the "feel good" chemical
• Low levels can cause norepinephrine to fall, but serotonin also has the potential to manipulate and indirectly raise norepinephrine

Cortisol and Depression

• Uncontrollable stress leads to elevated cortisol secretion
• This increases proinflammatory cytokines with the risk of developing depression
• Abnormalities involving thyroid hormones are also found

Stress-Induced Depression

• Accompanied by deficits in brain-derived neurotrophic factor (BDNF) and neurogenesis in the hippocampus.
• Animal models show antidepressant treatment reverses these deficits in hippocampal BDNF and neurogenesis

Pharmacotherapy Treatments

• Uses MAOIs, TCAs, SSRIs, and atypical antidepressants

Treatments for Manic and Bipolar Individuals

• Lithium or mood stabilizers are treatment options

Severe Depression/Mania Treatment

• ECT may be administered to severely depressed and manic individuals

Deep Brain Stimulation

• Shows promise as possible treatment for intractable depression

Anxiety Disorders

• Develop when normal fear and anxiety becomes persistent and uncontrollable

Panic Disorder

• Panic attacks with intense, spontaneous autonomic arousal
• Accompanied by lightheadedness, tachycardia, and difficulty breathing
• Heightened fear and anxiety can continue between panic attacks

BZ Receptor Binding Reduction

• Reduction in brain regions may contribute to panic disorder pathophysiology
• Include the hippocampus, insula, and prefrontal cortex

Panic Disorder Treatment

• CBT and antidepressants (TCAs and SSRIs) are generally effective

Benzodiazepines (BZs)

• Used as an adjunct or augmentation therapy for individuals nonresponsive to SSRIs or TCAs

Social Anxiety Disorder (SAD)

• Common disorder emerging in adolescence
• Includes fear and avoidance of social situations
• Individuals are very sensitive to being evaluated, embarrassed, or rejected

Neuroimaging Studies in SAD

• Reveal abnormal connections between the prefrontal cortex and the amygdala

Social Anxiety Disorder treatment (SAD)

• SSRI or SNRI medications, or cognitive therapies are options

Generalized Anxiety Disorder (GAD)

• Characterized by excessive and persistent worries about life events
• Motor disturbances, irritability, and fatigue correlate to psychosocial stress
• Individuals with GAD often manifest depression symptoms

GAD Pathophysiology

• Changes in the cingulate cortex and amygdala may play a role
• These changes stimulate anticipatory anxiety and attentional bias to threats

Generalized Anxiety Disorder (GAD) Treatment

• Treatment usually combines behavioral therapy and medications
• Especially 5-HT/NE reuptake inhibitors

PTSD

• Develops after exposure to a life-threatening or traumatic event
• Individuals experience recurring thoughts, flashbacks, and nightmares

PTSD Brain Alterations

• Structural/functional alterations exist in the amygdala, prefrontal cortex, and hippocampus
• Likely contributing to dysfunction in an emotional fear memory system

PTSD Treatment

• Difficult to treat chronic PTSD
• Involves psychotherapy and SSRI pharmacotherapy

Schizophrenia

• Characterized by thought disorders reflecting a break between cognition and emotion
• Classified into positive, negative, and cognitive categories

Schizophrenia Positive Symptoms

• Hallucinations, delusions, formal thought disorder, and bizarre behavior

Schizophrenia Negative Symptoms

• Flattened affect, alogia, anhedonia, attention deficits, and apathy
• Cognitive symptoms include inability to perform daily tasks requiring attention and planning

Brain Imaging Studies

• Show structural brain abnormalities, like enlarged cerebral ventricles
• Also widened fissures and sulci in the frontal cortex
• Reduced thalamus volumes may disrupt communication among cortical brain regions
• Temporal lobe may contribute to positive symptoms

Frontal Lobe in Schizophrenia

• Frontal lobe demonstrates progressive volume loss
• Worsening of negative symptoms occurs despite antipsychotic use
• Reduced blood flow and metabolism in the dorsolateral prefrontal cortex
• Compromising goal-directed behavior and cognitive problem-solving

First Generation Antipsychotic Drugs

• Block the dopamine D2 receptor

Second Generation Antipsychotics

• Called atypical antipsychotics, these block D2, dopamine, serotonin, and other neurotransmitter receptors

Antipsychotic Medications

• Not always effective in treating schizophrenic individuals with severe negative symptoms
• Talk therapies are implemented to increase drug compliance and encourage coping strategies

Definitions

• Delusion: A false belief that persists despite contradictory evidence
• Affective flattening: A lack of verbal or nonverbal expression of emotion
• Anhedonia: A lack of pleasure in activities that are normally pleasurable
• Psychosis: A psychiatric disorder that involves loss of contact with reality
• Hallucination: A perception that occurs in the absence of external stimuli
• Disorganized thinking: Inability to connect thoughts logically
• Mood disorder: Psychiatric disorder involving predominant emotions affecting societal function

Clinical Manifestations of Schizophrenia

• Positive: Delusions, Hallucinations, Incoherent speech (invented words), Wearing aluminum foil on head
• Negative: Social withdrawal, Blunted affect, Failure to respond to simple questions

GERD

• A chronic medical condition caused by stomach contents flowing upwards into the esophagus, resulting in symptoms and complications

GERD Symptoms

• Heartburn: Burning sensation in the chest
• Regurgitation: Fluid or food coming up into the chest

GERD & Lower Esophageal Sphincter

• People with GERD experience decreased resting tone of the lower esophageal sphincter
• Resulting in symptoms like heartburn and chronic cough

Obstructive GI Disorders

• Hiatal hernia and bowel obstruction

Types of Hiatal Hernia

• The most common is sliding
• Associated with gastro-esophageal reflux

Bowel Obstruction

• Caused by any condition preventing normal chyme flow through the intestinal lumen or failure of normal intestinal motility in the absence of an obstructing lesion (ileus)

Peptic Ulcer Disease (PUD)

• A circumscribed area of mucosal inflammation and ulceration
• Caused by excessive secretion of gastric acid and disruption of the protective mucosal barrier.

Peptic Ulcer Types

• Duodenal, gastric, and stress ulcers
• Duodenal and gastric ulcers are associated with H. pylori infection and chronic use of NSAIDs

Ulcerative Colitis (IBD)

• Symptoms include anemia, rectal bleeding, and bloody diarrhea

Crohn's Disease (IBD)

• Ask: Which part of the GI tract does damage occur?

Cirrhosis of the Liver

• Irreversible inflammatory disease of the liver
• Causes disorganization of lobular structure, fibrosis, and nodular regeneration
• Bile obstruction causes jaundice
• Vascular obstruction causes portal hypertension, shunting, and esophageal varices