Neurotransmitter-Disorder & Their Treatment

Introduction

Neurotransmitter-related disorders result from imbalances or dysregulation of neurotransmitters in the brain, impacting mental and emotional well-being. In this section, we will explore various neurotransmitter-related disorders and the available treatment options, including drugs acting as agonists or antagonists, enzyme inhibitors, and reuptake inhibitors.

Neurotransmitter-Related Disorders

1. Depression

• Depression is often associated with reduced levels of certain neurotransmitters, particularly serotonin and norepinephrine.
• Symptoms include persistent sadness, loss of interest in activities, changes in appetite and sleep patterns, and feelings of worthlessness.

2. Anxiety Disorders

• Conditions like generalised anxiety disorder (GAD) and panic disorder are linked to imbalances in neurotransmitters like serotonin, gamma-aminobutyric acid (GABA), and norepinephrine.
• Individuals experience excessive worry, fear, and panic attacks.

3. Schizophrenia

• Schizophrenia involves disturbances in thought processes, emotions, and perceptions.
• Dopamine dysregulation in the mesolimbic pathway is associated with schizophrenia symptoms.

4. Bipolar Disorder

• Bipolar disorder features extreme mood swings, with periods of mania and depression.
• Imbalances in neurotransmitters like dopamine, serotonin, and norepinephrine are implicated.

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Neurotransmitter-Related Disorders & Their Treatment

Treatment of Neurotransmitter-Related Disorders

1. Agonists

• These chemicals bind to and stimulate specific receptors, mimicking neurotransmitter action at synapses.
• In depression treatment, selective serotonin reuptake inhibitors (SSRIs) act as serotonin agonists by increasing synaptic serotonin levels.
• Examples include fluoxetine (Prozac) and sertraline (Zoloft).

2. Antagonists

• Antagonists bind to specific receptors, blocking neurotransmitter action at synapses.
• Antipsychotic medications used in schizophrenia act as dopamine antagonists, reducing the effects of excess dopamine in the mesolimbic pathway.
• Common antipsychotics include haloperidol and chlorpromazine.

3. Enzyme Inhibitors

• Some drugs inhibit enzymes that break down neurotransmitters, increasing their availability.
• Monoamine oxidase inhibitors (MAOIs) treat depression by inhibiting monoamine oxidase, which degrades serotonin, norepinephrine, and dopamine.
• Examples are phenelzine and tranylcypromine.

4. Reuptake Inhibitors

• Reuptake inhibitors prevent neurotransmitter reabsorption by the presynaptic neuron, enhancing their effects.
• Tricyclic antidepressants (TCAs) inhibit serotonin and norepinephrine reuptake, elevating synaptic levels.
• Amitriptyline and imipramine are TCAs.