You are here
Dr Stephen M. Stahl presents Psychotic & Cognitive Symptoms of Schizophrenia
Dr Stahl, MD, is a practicing psychiatrist in Carlsbad, USA, and the author of best-selling textbook, Essential Psychopharmacology. In this video the currently known circuits and receptors linked to the symptom dimensions of schizophrenia are reviewed, together with the therapeutic mode of action of antipsychotics as D2 antagonists and partial agonists. Finally, atypical antipsychotic drugs and their potential glutamate-linked actions are introduced.
All antipsychotics work by blocking the positive signal pathway that is over-activated. Most work by dopamine D2 antagonism, blocking the dopamine receptor. Atypical drugs are multifunctional and provide 5-HT2A antagonism affecting both pharmacologic and clinical actions. Dr. Stahl explains the importance of glutamate, a neurotransmitter used by all neurons. In normal situations NMDA binds to its receptor on GABA interneurons, stimulating GABA, reducing glutamate production by glutamate neurons. This helps keeping most of the brain in the off-state. In schizophrenia it is suggested ketamine is blocking the NMDA receptor, avoiding GABA upregulation, resulting in (over) activation of glutamate neurons, resulting in glutamate production and chaos in the brain. The new drug target is therefore now glutamate.
Suggested further reading:
This is of the first part of a four-part series on psychopharmacology - view the 2nd Dr Stahl Presentation here.
Download the Powerpoint presentation from Dr. Stahl's Psychopharmacology Workshop “Optimizing Care for Patients with Schizophrenia – Symptom, Circuits, and Neurotransmitters and the Antipsychotic Armamentarium”.