Physiological Psychology and Psychopharmacology Lecture Notes

Neurological Disorders

• Traumatic Brain Injury (TBI)

  • Causes: Blows or jolts to the head, can be open (penetrating) or closed.

  • Symptoms depend on injury severity and location:

  • Widespread damage, loss of consciousness, emotional/cognitive/behavioral/physical symptoms.

  • Anterograde amnesia (difficulty forming new memories) and retrograde amnesia (loss of old memories).

  • Duration of anterograde amnesia helps assess injury severity and predict recovery.

  • Most patients recover significantly in three months; moderate to severe cases may have indefinite symptoms.

  • Common Psychiatric Diagnosis: Major Depressive Disorder.

• Cerebrovascular Accident (Stroke)

  • Non-traumatic interruption of blood flow to the brain.

  • Leading risk factor: Hypertension; other factors include atrial fibrillation, atherosclerosis, diabetes, smoking, and high cholesterol.

  • Symptoms vary by artery affected:

  • Middle Cerebral Artery: Contralateral sensory loss, weakness (especially arm/face), impaired vision, and aphasia (if dominant hemisphere).

  • Anterior Cerebral Artery: Contralateral sensory loss, weakness (especially leg), confusion, apathy.

  • Posterior Cerebral Artery: Memory deficits, unilateral cortical blindness, color agnosia.

• Huntington's Disease

  • Genetic disorder, autosomal dominant gene; linked to abnormal GABA, glutamate, and dopamine levels.

  • Symptoms: Onset typically at 30-50 years; early symptoms include depression and ineffective mood, followed by cognitive impairments (e.g., memory loss) and motor symptoms (e.g., clumsiness, fidgeting).

  • Progression leads to severe motor symptoms and potential neurocognitive disorders.

• Parkinson's Disease

  • Caused by degeneration of dopamine-producing cells in the substantia nigra.

  • Symptoms: Impaired balance, rigidity, slowed movement, and tremors (especially pill rolling).

  • Mental health implications: Depression in 50% of patients, anxiety in 40%.

  • Treatment: L-DOPA for early-stage motor symptoms.

• Seizure Disorders

  • Caused by abnormal electrical activity; classified into focal onset and generalized onset seizures.

  • Focal Onset Seizures:

  • Begin in one area; can be simple (focal aware) or complex (impaired awareness).

  • Symptoms vary based on the origin, e.g., automatisms or hallucinations.

  • Generalized Onset Seizures: Affect both sides of the brain; divided into motor (tonic-clonic/grand mal) and non-motor (absence/petite mal).

Psychopharmacology

• Antipsychotics

  • First Generation (Traditional): Used for schizophrenia and psychotic disorders.

  • Mechanism: Dopamine antagonists that block receptors.

  • Side effects:

    • Anticholinergic (dry mouth, confusion).

    • Extrapyramidal (e.g., tardive dyskinesia). Can be severe and irreversible.

  • Second Generation (Atypical): Often preferred; can treat both positive and negative symptoms of schizophrenia.

  • Mechanism: Dopamine and serotonin antagonists.

  • Side Effects:

    • Less extrapyramidal risk, but possible agranulocytosis (low WBC).

    • Metabolic syndrome concerns.

• Antidepressants

  • SSRIs (Selective Serotonin Reuptake Inhibitors): First-line treatment for major depressive disorders.

  • Side effects: Mild anticholinergic, gastrointestinal issues, sexual dysfunction.

  • SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors): Used for severe depression and anxiety disorders.

  • Side effects can impact blood pressure.

  • Tricyclic Antidepressants: Effective but riskier due to cardiotoxicity and sedation effects.

  • MAOIs (Monoamine Oxidase Inhibitors): Used for atypical depression; can pose dietary restrictions due to potential interactions with tyramine-rich foods.

Traumatic Brain Injury (TBI)

Causes: Blows or jolts to the head, which can be either open (penetrating) or closed. Common causes include falls, motor vehicle accidents, and sports injuries.

Symptoms: Depend on injury severity and location:

• Widespread damage may lead to loss of consciousness.

• Emotional symptoms: mood swings, irritability, and depression.

• Cognitive symptoms: confusion, memory problems, and difficulty concentrating.

• Physical symptoms: headaches, dizziness, and fatigue.

• Anterograde amnesia (difficulty forming new memories) and retrograde amnesia (loss of old memories).

Assessment: Duration of anterograde amnesia is crucial to assess injury severity and predict recovery. Extended periods of amnesia can suggest more severe brain damage.

Recovery: Most patients recover significantly within three months; however, moderate to severe cases may experience lingering symptoms, including chronic pain or cognitive difficulties.

Common Psychiatric Diagnosis: Major Depressive Disorder.

Cerebrovascular Accident (Stroke)

Definition: A non-traumatic interruption of blood flow to the brain. It can be ischemic (caused by a blockage) or hemorrhagic (caused by bleeding).

Leading Risk Factor: Hypertension; other risks include atrial fibrillation, atherosclerosis, diabetes, smoking, and high cholesterol.

Symptoms: Vary by artery affected:

• Middle Cerebral Artery: Contralateral sensory loss, weakness (especially in the arm or face), impaired vision, and aphasia (language difficulties, particularly if the dominant hemisphere is affected).

• Anterior Cerebral Artery: Contralateral sensory loss, weakness (especially in the leg), confusion, and apathy.

• Posterior Cerebral Artery: Memory deficits, unilateral cortical blindness, and color agnosia.

Huntington's Disease

Genetic Basis: An autosomal dominant disorder caused by a mutation in the HTT gene, leading to the production of the huntingtin protein, which is toxic to neurons.

Symptoms: Onset typically occurs between 30-50 years. Early symptoms include:

• Depression and mood instability.

• Cognitive impairments, such as memory loss and difficulty with decision-making.

• Motor symptoms, including clumsiness and involuntary movements (chorea).

Progression: The disease progressively worsens, leading to severe motor symptoms, and it may result in neurocognitive disorders affecting daily functioning.

Parkinson's Disease

Etiology: Caused by degeneration of dopamine-producing cells in the substantia nigra, leading to disruptions in the basal ganglia circuits responsible for movement.

Symptoms: Include impaired balance, muscle rigidity, slowed movement (bradykinesia), and tremors (notably the “pill rolling” tremor of hands).

Mental Health Implications: Depression affects approximately 50% of patients, and anxiety is prevalent in about 40%, often worsening the quality of life.

Treatment: Typically involves L-DOPA (levodopa) to replenish dopamine levels in the brain, which is more effective in early-stage motor symptoms but may have diminishing effects over time.

Seizure Disorders

Definition: Caused by abnormal electrical activity in the brain, these disorders are classified into focal onset and generalized onset seizures.

Focal Onset Seizures:

• Begin in one specific area of the brain. They can be simple (focal aware—without altered awareness) or complex (impaired awareness). Symptoms vary based on the region, potentially including automatisms (repetitive movements) or hallucinations.

Generalized Onset Seizures:

• Affect both sides of the brain and are typically divided into two categories: motor (e.g., tonic-clonic or grand mal seizures) and non-motor (e.g., absence or petite mal seizures).

Psychopharmacology

Antipsychotics

First Generation (Traditional): Used for treating schizophrenia and other psychotic disorders:

• Mechanism: Act as dopamine antagonists, blocking dopamine receptors in the brain.

• Side Effects: Include anticholinergic effects (dry mouth, confusion) and extrapyramidal symptoms such as tardive dyskinesia, which can be severe and irreversible.

Second Generation (Atypical): Often preferred for their broader efficacy:

• Mechanism: Involve both dopamine and serotonin antagonism.

• Side Effects: Less risk of extrapyramidal symptoms but may cause agranulocytosis (low white blood cell count) and metabolic syndrome concerns (weight gain, diabetes).

Antidepressants

SSRIs (Selective Serotonin Reuptake Inhibitors): The first-line treatment for major depressive disorders:

• Side Effects: Mild anticholinergic effects, gastrointestinal issues, and sexual dysfunction.

SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors): Effective for severe depression and anxiety:

• Side Effects: Can impact blood pressure and may cause withdrawal symptoms upon discontinuation.

Tricyclic Antidepressants: Effective but with risks:

• Risks: Cardiovascular toxicity and sedation effects limit their use.

MAOIs (Monoamine Oxidase Inhibitors): Used for atypical depression:

• Considerations: Require dietary restrictions due to potential interactions with tyramine-rich foods leading to hypertensive crises.