Chapter 13: Psychiatric Disorders

In this Chapter…

• Anxiety Disorders
• Tourette Syndrome
• Major Depression
• Bipolar Disease
• Schizophrenia

Anxiety Disorders

• Anxiety disorders include:
  • OCD (Obsessive Compulsive Disorder)
  • Panic disorder
  • Phobias
  • acrophobia- fear of heights
  • agoraphobia- fear of open spaces)
  • Social anxiety disorder
  • Generalized anxiety disorder
  • PTSD (Post-traumatic stress disorder)
• Anxiety disorders often occur with depression
  • These individuals are at a high risk of suicide

OCD

• Individuals become trapped in repetitive thoughts and behaviors that don’t have a reason but cannot seem to stop
• Environmental factors and genetics probably play a role in the development of this disorder
• PET scans can reveal abnormalities in the cortical and deep brain
  • Shows that there are changes in the Central Nervous System that occur in those with OCD
• Dogs that develop acral lick syndrome respond to the serotonergic antidepressant clomipramine
  • Other serotonergic antidepressants are effective in treating OCD
  • “Serotonergic” refers to a substance that interacts with serotonin
• Behavioral intervention or exposure and response prevention is effective for many OCD patients

Panic Disorder and Phobias

• Phobia: intense, irrational fear of a particular object or situation
• Panic disorders and phobias have similar neurochemical underpinnings that come up as the result of a particular stressor
• Panic disorders and phobias usually start unexpectedly
• Individuals experience an overwhelming sense of impending doom
  • Other symptoms include:
  • Sweating
  • Weakness
  • Dizziness
  • Shortness of breath
• More attacks bring about more anxiety for the next panic attack
• People avoid public settings where attacks might occur
  • Individuals with panic disorders/phobias may develop agoraphobia if they are untreated
• Antidepressants (SSRIs) and cognitive behavioral therapy are effective treatments

Post-Traumatic Stress Disorder (PTSD)

• Extreme stressors can lead to the formation of stress that can last a lifetime
• PTSD is characterized by:
  • Intense fear
  • Helplessness
  • Horror
  • Intrusive recollections of the traumatic event
  • Avoidance and numbing
  • Hyperarousal
• PTSD is associated with:
  • Dysregulation of stress hormones
  • Disordered sleep
  • Major depressive disorder
• Very high levels of norepinephrine released in the brain during the traumatic event remain at those heightened levels
• The alpha-1 blocker prazosin that was used to lower blood pressure is now also used to treat nightmares experienced with PTSD
  • Beta-blockers such as propranolol are also being tested in individuals exposed to trauma
  • These must be administered shortly after the traumatic incident
• PTSD is generally treated with
  • Antidepressants
  • Atypical antipsychotic medication
  • Cognitive behavioral therapy
  • Eye movement desensitization
  • Reprocessing therapy
• Benzodiazepines can also be used to treat PTSD
  • Benzodiazepines bind to GABA receptors and enhance the responsiveness to endogenous GABA

Tourette Syndrome/Tourette’s

• Tourette’s is an inherited disorder
• Symptoms usually appear between the ages of 4 and 8
• Symptoms
  • Tics: a habitual spasmodic contraction of the muscles, most often in the face
  • These can either be motor or vocal
  • Types of tics may change and can increase or decrease in severity
  • Repetitive involuntary movements or utterances that are sudden and rapid and persist for 1 or more years
• Many people with Tourette's have associated conditions including:
  • Problems with learning
  • Difficulties paying attention
  • Obsessive thoughts
  • Compulsive rituals
  • These symptoms all seem to result from abnormal activity in the basal ganglia
• Genes and uterine or early environmental conditions can cause abnormalities in basal ganglia development or an excess of some chemicals
• The stimulants methylphenidate and dextroamphetamine are reported to improve attention and decrease tics in patients with Tourette syndrome
  • However, reactions to these medications can include:
  • Weight gain
  • Muscular rigidity
  • Fatigue
  • Motor restlessness
  • Social withdrawal
  • Depression
  • Cognitive impairment
• Other types of therapy include
  • Behavioral therapy
  • Psychotherapy
  • Counseling

Major Depression

• Symptoms of major depression include:
  • Harrowing feelings of sadness
  • Fopelessness
  • Pessimism
  • Loss of interest in life
  • Reduced emotional well-being
• Major depression is also associated with:
  • Disturbances in sleep and appetite
  • Decreased energy levels
  • Cognitive disturbances, including difficulty concentrating and remembering
• Genes and environment play a role in one’s risk for depression
  • stress plays a role in triggering a depressive episode
• Physical symptoms may reflect disturbances in the hypothalamus
  • This results in excessive production of stress hormones
• PET scans show the anterior cingulate gyrus in the prefrontal cortex is affected in depression
• Current medications increase levels of norepinephrine or serotonin in synapses
  • Some also target dopamine
  • SSRIs (selective serotonin reuptake inhibitors) act on serotonin alone
  • Increased levels of neurotransmitters start changes in cells and circuits
  • Ketamine: a drug that blocks NMDA glutamate receptors
  • It has been shown to alleviate symptoms of depression
  • There are many side effects
• Cognitive-behavioral psychotherapies have shown to be effective for treating major depression

Bipolar Disorder

• Bipolar disorder was previously known as manic-depressive illness
• Individuals with Bipolar disorder have an increased risk of suicide
• Individuals usually experience episodes of deep depression and manic highs
  • Depressive episodes are indistinguishable from those of major depression
  • Manic episode symptoms include:
  • Increased energy
  • Decreased need for sleep
  • Marked interest in goal-directed activities
  • Poor judgement
  • Predominantly irritability but maybe euphoria as well
• Manic individuals are grandiose and may have hallucinations or delusions
  • Hypomania: a milder form of mania that can still be present in Bipolar disorder
• People with Bipolar disorder have recurrences of acute mania/depression throughout their life
• Bipolar disorder has a high genetic influence
• Lithium has a mood-stabilizing effect
  • Individuals may require additional treatments, especially in the depressive episodes

Schizophrenia

• Schizophrenia is marked by disturbances in
  • Thinking and cognition
  • Emotional reactions
  • Social behavior
• This results in chronic illness and personality change
• Schizophrenia is caused by disruption of neurodevelopment through genetic disposition
  • Maternal infections & direct brain trauma increase the severity of schizophrenia
• Brain scans and postmortems of those with schizophrenia show abnormalities in the brain
  • Enlarged ventricles and reduced size of certain brain regions
  • Ventricles: open areas deep within the brain that store cerebrospinal fluid
  • PETs and fMRIs taken when performing cognitive tasks show abnormal function in some brain areas
• Brain systems using dopamine, glutamate, and GABA appear to be involved in the development of schizophrenia
  • Genes involved in controlling neuron communication have been identified to increase the risk of schizophrenia
• Schizophrenia is usually diagnosed between the ages of 15 and 25
• Most patients continue to have moderate or severe symptoms that may be aggravated by life stressors
  • Deficits in cognition are frequent
  • There are lifelong manifestations of schizophrenia
  • Positive symptoms- symptoms that “add” something, including:
    • hallucinations
    • delusions
    • confused thinking
  • Negative symptoms- symptoms that “take away” something, including:
    • inability to experience pleasure
    • lack of motivation
  • Schizophrenia can make it difficult for people to lead productive lives
• Treatments
  • Chlorpromazine: the first antipsychotic drug discovered in the 1950’s by accident
  • It is more effective than a placebo or sedative
  • The first generation of antipsychotic drugs act by inhibiting certain dopamine receptors
  • However, this accounts for the high prevalence of side effects like Parkinson’s disease and tardive dyskinesia
    • Tardive dyskinesia: an irreversible movement disorder characterized by involuntary and abnormal movements in the jaw, lips, or tongue
  • The second generation of drugs treat positive symptoms but don’t have the same likelihood of causing side effects such as Parkinson’s disease
  • Side effects of these drugs include:
    • Lots of weight gain
    • Blood disorders
    • Muscle pain & dysfunction