In-Depth Notes on Psychiatric Disorders

Causes of Psychiatric Disorders

  • Psychiatric disorders arise from various factors, including genetics and environmental influences.

    • Genetic Factors: Many disorders run in families, but familial ties do not guarantee the development of similar disorders.

    • Environmental Factors:

    • Negative Factors: Life stresses, medical conditions, personal relationships; examples include death of a loved one, poverty, addiction, or trauma from violence.

    • Positive Factors (Resilience Factors): Support from family/friends, good coping skills, physical activity, engaged in various activities.

Anxiety Disorders and PTSD

  • Anxiety is typically a normal response to danger but becomes unhealthy in psychiatric disorders like PTSD, OCD, and panic attacks.

  • Prevalence: Anxiety disorders are the most common mental health disorders in the US, more prevalent among women, for reasons that are not clear but likely include both sex differences (biological) and gender differences (psychosocial).

  • Treatment:

    • Medications:

    • SSRIs (Selective Serotonin Reuptake Inhibitors) raise serotonin levels.

    • Benzodiazepines (e.g., Valium) were historically used but have a dependency risk, thus less favored now.

      (Benzodiazepines (such as diazepam, or Valium) were once the standard medication for anxiety because they boost levels of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). GABA acts like a “brake pedal” on neurons, helping to decrease their activity, especially in areas of the brain important in anxiety.)

Obsessive-Compulsive Disorder (OCD)

  • Characterized by:

    • Obsessions: Uncontrollable thoughts (e.g., fear of contamination, need for perfection).

    • Compulsions: Ritualistic behaviors (e.g., excessive hand washing, checking for mistakes).

  • Prevalence: Affects ~1% of U.S. adults, usually diagnosed around 19 years.

  • Neuroscience:

    • Abnormalities in the basal ganglia involvement linked to habits and reward systems affected in OCD.

      (The basal ganglia are also involved in the brain’s reward sys tem, our ability to feel good, and in learning and memory; these functions are mediated by the neurotransmitters dopamine, serotonin, and glutamate, respectively.)

  • Treatment:

    • SSRIs, clomipramine (a tricyclic antidepressant), behavioral therapies, and in some, deep brain stimulation (DBS). + neuroleptic (tranquilizing) drugs may also be prescribed to help manage severe symptoms, particularly when other treatments have not been effective.

      Clomipramine (a tricyclic antidepressant):

      Clomipramine works by blocking the reuptake of serotonin and norepinephrine, increasing their availability in the synaptic cleft, which is beneficial for reducing OCD symptoms. It has been found effective in treating obsessive thoughts and compulsive actions.

Panic Disorder

  • Defined by unexpected panic attacks with physical symptoms like rapid heartbeat or dizziness.

  • Affects about 2.7% of U.S. adults.

  • Often co-occurs with mood disorders and is treated with SSRIs or benzodiazepines in emergencies.

Post-Traumatic Stress Disorder (PTSD)

  • Triggered by traumatic events, leading to severe symptoms like nightmares and hyperarousal.

  • Symptoms may take time to develop and can be persistent.

  • Cognitive Behavioral Therapy (CBT) is the primary treatment.

  • Neurological impacts include changes in hippocampus and prefrontal cortex sizes, affecting memory and emotional processing.

  • Treatment Medications: SSRIs and norepinephrine blockers (e.g., prazosin and propranolol).

    The primary medications used to treat Post-Traumatic Stress Disorder (PTSD) include Selective Serotonin Reuptake Inhibitors (SSRIs) and norepinephrine blockers, such as prazosin and propranolol.

    1. **Selective Serotonin Reuptake Inhibitors (SSRIs)**

    - SSRIs are commonly prescribed for their ability to increase serotonin levels in the brain, which can help alleviate symptoms of anxiety and depression commonly associated with PTSD. - By enhancing serotonin activity, SSRIs can improve mood, reduce stress responses, and contribute to emotional stability in individuals suffering from PTSD.

    2. **Norepinephrine Blockers**:

    - **Prazosin**: (blood-pressure medication)

    - Prazosin is primarily used to treat nightmares and other sleep disturbances related to PTSD. - It works by blocking alpha-1 adrenergic receptors, leading to a reduction in sympathetic nervous system activity, which is often heightened in PTSD patients.

    - **Propranolol**:

    - Propranolol is a beta-blocker that can help manage the physical symptoms of anxiety, such as rapid heartbeat and trembling. - It may also assist in reducing the emotional response to trauma memories, helping some patients process their experiences without overwhelming fear or anxiety. These medications are effective as part of a comprehensive treatment plan, often alongside therapies like Cognitive Behavioral Therapy (CBT), to provide a well-rounded approach to treating PTSD symptoms.

    -The neurotransmitter neuropeptide Y also appears to offer some protection against developing PTSD.

  • Many people with PTSD have a smaller hippocampus (the brain region integral for learning and memo ry) and a smaller prefrontal cortex (the part of the brain that helps control thinking, emotions, and behavior). In contrast, the brain’s emotional center, the amygdala, is apparently overactive in responding to stimuli in people with PTSD.

  • Genes affecting PTSD risk also affect the risk for major depres sion, generalized anxiety disorder, and panic disorder — suggesting common biological components of these psychi atric conditions.

Mood Disorders

  • Mood disorders characterize prolonged emotional states distinct from normal mood fluctuations.

  • Two main types:

    • Major Depression:

    • Diagnosed when at least four criteria persist for two weeks, such as sadness, appetite changes, and sleep issues.

    • Affects ~7% of Americans, often leading to severe disability.

    • Often, depression is ac companied by other diseases.

    • Inside the brain, depression appears to disrupt the hypothalamus.

    • The monoamine neurotransmitter systems, which include dopamine and serotonin, are also disrupted.

    • People with depression tend to have a smaller hippocampus and prefrontal cortex.

    • Treatment:

      1. **Selective Serotonin Reuptake Inhibitors (SSRIs)**: - Block the reuptake of serotonin, increasing its availability in the synapses.

      2. **Norepinephrine-Dopamine Reuptake Inhibitors (NDRIs)**: - Raise levels of norepinephrine and dopamine in the brain, thought to help alleviate depressive symptoms.

      3. **Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)**: - Increase levels of both serotonin and norepinephrine.

      4. **Tricyclic Antidepressants (TCAs)**: - Affect various neurotransmitters, including serotonin and norepinephrine, but generally are not as commonly used as SSRIs due to side effects.

      5. **Atypical Antidepressants**: - These can vary widely in their mechanisms and include medications that affect dopamine and norepinephrine.

      Treatment typically combines medications with **Cognitive Behavioral Therapy (CBT)**, which focuses on changing negative thought patterns and improving emotional resilience.

    • Bipolar Disorder:

    • Characterized by mood swings from manic highs (energy, sleeplessness) to depressive lows (sadness, hopelessness).

    • High, or manic, episodes involve boundless energy, racing thoughts, and insomnia; they may also involve substance abuse and harmful behaviors like risky sex or other unsafe activities.

    • During low, or depressive, episodes, people with bipolar disorder feel very sad and hopeless, worried, and some times suicidal.

    • Some individuals with bipolar disorder are hypomanic; they are highly productive, feel great, and function better than normal.

    • Treatment is complex, often requiring multiple medications.
      (Medications such as anti-epilepsy drugs, lithium, or atypical antipsychotics are used during manic periods to help stabilize mood and reduce the intensity of manic symptoms. These medications work by modulating neurotransmitters and stabilizing electrical activity in the brain, which can alleviate excessive energy and impulsivity seen during manic episodes. During depressive periods, antidepressants are often prescribed to help raise mood and alleviate symptoms of depression. Cognitive Behavioral Therapy (CBT) is employed alongside medications to change negative thought patterns and improve emotional resilience, aiding in the management of depressive symptoms. The complexity of bipolar disorder often necessitates a combination of these treatments, ensuring comprehensive care throughout the mood swings associated with the condition.)

1. Anti-Epileptic Drugs (Mood Stabilizers)

Examples: Valproate (Depakote), Lamotrigine (Lamictal), Carbamazepine

🔬 How They Work:

  • Originally designed to prevent seizures, but they also help stabilize mood.

  • They calm overactive neurons by affecting ion channels and neurotransmitter release (especially GABA, an inhibitory neurotransmitter).

  • They reduce the risk of manic and depressive episodes.

🧪 2. Lithium

🔬 How It Works:

  • One of the oldest and most effective mood stabilizers.

  • It helps normalize neurotransmitter activity (like dopamine, serotonin, and glutamate) and regulates cellular signaling.

  • Lithium reduces the frequency and intensity of both mania and depression.

  • It also reduces suicidal thoughts, even in people without severe depression.

⚠ Requires regular blood monitoring — too much can be toxic.

🧩 3. Atypical Antipsychotics

Examples: Olanzapine, Quetiapine, Risperidone, Aripiprazole

🔬 How They Work:

  • Block or balance dopamine and serotonin receptors in the brain.

  • Help control manic symptoms like delusions, agitation, or racing thoughts.

  • Some (like Quetiapine) also help with bipolar depression.

🌧 4. Antidepressants (For Depressed Periods)

Examples: SSRIs (like fluoxetine), SNRIs

🔬 How They Work:

  • Increase levels of serotonin, norepinephrine, or dopamine in the brain.

  • These chemicals are often low during depression, so antidepressants help restore balance and improve mood, sleep, and energy.

⚠ In bipolar disorder, antidepressants are usually combined with a mood stabilizer to prevent triggering a manic episode.

🧠 5. Cognitive Behavioral Therapy (CBT)

🧘 How It Works:

  • A talk therapy that helps people recognize and change negative thought patterns.

  • Improves coping strategies, emotion regulation, and awareness of mood changes.

  • Often used alongside medication to reduce relapse and improve daily functioning.

Disorders of Cognition: Schizophrenia

  • A severe disorder disrupting thought, emotion, and behavior, appearing typically in late teens to mid-20s.

  • Symptoms are both positive (hallucinations, delusions) and negative (lack of motivation): They experience “positive” symptoms such as hallucinations, delusions, and confused thinking, and “negative” ones, including an inability to expe rience pleasure and a severe lack of motivation.

  • Treatment Options:

    • Antipsychotics that typically dampen dopamine responses are the mainstay but may lead to movement disorders.

    • Chlorpromazine, the first antipsychotic drug, works by damping the dopamine response, which is thought to drive schizophrenia’s “positive” symptoms.

    • The most recently developed drugs also suppress some serotonergic activity, which seems to help with the negative symptoms of schizophrenia.

  • Genetic links are significant, with ongoing research identifying genetic factors influencing the disorder.

  • Nicotine seems to relax rigid nerve-cell shape and function in areas of the brain affected by schizophrenia. Thus, drugs contain ing nicotine may prove to be useful as future treatments for schizophrenia.