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

\ \