Neurotransmitter dysfunctions associated with various mental health and neurological disorders

Schizophrenia

• Dopamine: High levels, particularly in certain brain areas like the striatum, contribute to symptoms such as hallucinations and delusions. The dopamine hypothesis of schizophrenia posits that overactivity of dopamine transmission is a core feature of the disorder.

Alzheimer's Disease

• Acetylcholine (ACh): Low levels due to the degeneration of cholinergic neurons. This neurotransmitter is crucial for memory and learning, and its deficit is associated with cognitive decline in Alzheimer's patients. The gist of Alzheimer’s disease

Depression

• Serotonin: Low levels are linked to mood regulation problems. Serotonin is involved in mood, emotion, and sleep.
• Norepinephrine (NE): Low levels contribute to lethargy, lack of interest, and depressive symptoms. Norepinephrine affects attention and responding actions.

Parkinson's Disease

• Dopamine: Low levels due to the degeneration of dopaminergic neurons in the substantia nigra. This leads to motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement).

Huntington's Disease

• Acetylcholine (ACh): Low levels due to the degeneration of cholinergic neurons in the basal ganglia. This contributes to motor dysfunction and cognitive decline.

Anxiety Disorders

• Gamma-Aminobutyric Acid (GABA): Low levels. GABA is the primary inhibitory neurotransmitter in the brain, and its deficiency can lead to increased neuronal excitability and anxiety symptoms.

Mania (Bipolar Disorder)

• Serotonin: High levels during manic episodes contribute to elevated mood and hyperactivity.
• Norepinephrine (NE): High levels, leading to increased arousal and energy, and contributing to manic symptoms.

Additional Information for Context:

Post-Traumatic Stress Disorder (PTSD)

• Cortisol: Often lower levels, affecting the stress response.
• Norepinephrine: Elevated levels, contributing to hyperarousal and heightened stress responses.
• Serotonin: Dysregulation can affect mood and anxiety levels.
• Oxytocin: Lower levels can impact social bonding and stress regulation.

Bipolar Disorder

• Cortisol: Dysregulated levels, often elevated during manic episodes.
• Thyroid Hormones: Abnormal levels can influence mood swings.
• Dopamine: Elevated during manic phases, reduced during depressive phases.

Generalized Anxiety Disorder (GAD)

• Cortisol: Often higher levels due to chronic stress.
• Norepinephrine: Elevated, contributing to anxiety symptoms.
• Serotonin: Dysregulation affecting mood.

Obsessive-Compulsive Disorder (OCD)

• Serotonin: Typically lower, affecting mood and behavior regulation.
• Glutamate: Potentially elevated, contributing to compulsive behaviors.
  ERN Topography: ERN abnormalities suggest that OCD is characterized by excessive and prolonged error processing, supporting models that propose hyperactive cognitive control systems and dysfunctional error monitoring as core features of the disorder.

Attention Deficit Hyperactivity Disorder (ADHD)

• Dopamine: Lower levels in the prefrontal cortex, impacting attention and impulse control.
• Norepinephrine: Dysregulated, affecting focus and behavior.

Autism Spectrum Disorder (ASD)

• Serotonin: Abnormal levels, impacting mood and social behavior.
• Oxytocin: Lower levels, affecting social bonding.
• Glutamate and GABA: Imbalances contributing to neurological and behavioral symptoms.

Eating Disorders (Anorexia Nervosa, Bulimia Nervosa)

• Serotonin: Dysregulation affecting mood and appetite.
• Dopamine: Abnormal levels, impacting reward pathways and eating behavior.
• Leptin and Ghrelin: Imbalance in hunger and satiety hormones.

Understanding the role of these neurotransmitters in various disorders helps in tailoring specific treatments and therapeutic strategies to manage and alleviate symptoms effectively.

Reference:

1. Schizophrenia:

   • Howes, O. D., & Kapur, S. (2009). The dopamine hypothesis of schizophrenia: Version III--the final common pathway. Schizophrenia Bulletin, 35(3), 549-562.
     https://pubmed.ncbi.nlm.nih.gov/19325164/
     

2. Alzheimer's Disease:

   • Francis, P. T., Palmer, A. M., Snape, M., & Wilcock, G. K. (1999). The cholinergic hypothesis of Alzheimer's disease: a review of progress. Journal of Neurology, Neurosurgery, and Psychiatry, 66(2), 137-147. https://pubmed.ncbi.nlm.nih.gov/10071091/

3. Depression:

   • Ressler, K. J., & Nemeroff, C. B. (2000). Role of serotonin in the pathophysiology of depression: focus on the serotonin transporter. Clinical Chemistry, 46(8), 1372-1381.  
   •  https://pubmed.ncbi.nlm.nih.gov/19498050/
   • Delgado, P. L. (2000). Depression: the case for a monoamine deficiency. The Journal of Clinical Psychiatry, 61(Suppl 6), 7-11. https://psycnet.apa.org/record/2000-03492-002

4. Parkinson's Disease:

   • Dauer, W., & Przedborski, S. (2003). Parkinson's disease: mechanisms and models. Neuron, 39(6), 889-909. https://www.cell.com/fulltext/S0896-6273(03)00568-3

5. Huntington's Disease:

   • Reiner, A., Albin, R. L., Anderson, K. D., D'Amato, C. J., Penney, J. B., & Young, A. B. (1988). Differential loss of striatal projection neurons in Huntington disease. Proceedings of the National Academy of Sciences, 85(15), 5733-5737. 
     https://pubmed.ncbi.nlm.nih.gov/2456581/
     

6. Anxiety Disorders:

   • Nutt, D. J., & Malizia, A. L. (2001). New insights into the role of the GABA(A)-benzodiazepine receptor in psychiatric disorder. The British Journal of Psychiatry, 179(5), 390-396. https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/new-insights-into-the-role-of-the-gabaabenzodiazepine-receptor-in-psychiatric-disorder/9BD003AF11C2BD763447C80464D3FAAA

7. Bipolar Disorder and Mania:

   • Belmaker, R. H. (2004). Bipolar disorder. New England Journal of Medicine, 351(5), 476-486. https://www.nejm.org/doi/abs/10.1056/NEJMra035354
   • Manji, H. K., & Lenox, R. H. (2000). Signaling: cellular insights into the pathophysiology of bipolar disorder. Biological Psychiatry, 48(6), 518-530.
     https://www.sciencedirect.com/science/article/abs/pii/S000632230000929X

8. Post-Traumatic Stress Disorder (PTSD):

   • Yehuda, R. (2002). Post-traumatic stress disorder. New England Journal of Medicine, 346(2), 108-114. https://www.nejm.org/doi/full/10.1056/NEJMra012941
   • Bremner, J. D., & Vermetten, E. (2001). Stress and development: Behavioral and biological consequences. Development and Psychopathology, 13(3), 473-489.

9. Obsessive-Compulsive Disorder (OCD):

   • Pittenger, C., & Bloch, M. H. (2014). Pharmacological treatment of obsessive-compulsive disorder. Psychiatric Clinics, 37(3), 375-391. https://pubmed.ncbi.nlm.nih.gov/25150568/

10. Attention Deficit Hyperactivity Disorder (ADHD):

    • Volkow, N. D., Wang, G. J., Newcorn, J., Telang, F., Solanto, M. V., Fowler, J. S., ... & Swanson, J. M. (2007). Brain dopamine transporter levels in treatment and drug naive adults with ADHD. Neuroimage, 34(3), 1182-1190. https://www.sciencedirect.com/science/article/abs/pii/S105381190601024X

11. Autism Spectrum Disorder (ASD):

    • Fatemi, S. H., Aldinger, K. A., Ashwood, P., Bauman, M. L., Blaha, C. D., Blatt, G. J., ... & Welsh, J. P. (2012). Consensus paper: Pathological role of the cerebellum in autism. The Cerebellum, 11(3), 777-807. https://pubmed.ncbi.nlm.nih.gov/22370873/

12. Eating Disorders:

    • Kaye, W. H., Frank, G. K., Bailer, U. F., Henry, S., Meltzer, C. C., Price, J. C., ... & Wagner, A. (2005). Serotonin alterations in anorexia and bulimia nervosa: new insights from imaging studies. Physiology & Behavior, 85(1), 73-81.
      https://www.sciencedirect.com/science/article/abs/pii/S0031938405001198

These references should provide a comprehensive understanding of the neurotransmitter dysfunctions associated with these disorders.

 

© 2000-2025 Sieglinde W. Alexander. All writings by Sieglinde W. Alexander have a fife year copy right. Library of Congress Card Number: LCN 00-192742 ISBN: 0-9703195-0-9