- A risk of taking SSRIs
- Many over-the-counter drugs may synergize with the drugs to push synaptic serotonin levels too high
- Symptoms include confusion, muscle spasms, and fever

Michigan State University

- Monoamine hypothesis
- Monoamine Oxidase (MAO)
- Reserpine
- Tricyclics
- Selective serotonin reuptake inhibitors (SSRIs)

Drug Treatments for Depressive Disorders

Breedlove, S. & Watson, N. (2017). Behavioral neuroscience, eighth edition. Oxford University Press.

Behavioral Neuroscience 8th Edition

Serotonin Syndrome

Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs used to treat conditions like depression, which is often associated with low serotonin levels. Unlike agonists or antagonists that bind to receptors, SSRIs work by blocking the reuptake process. This action prevents unused serotonin from being reabsorbed by the presynaptic neuron, allowing it to remain in the synaptic cleft for a longer period. The extended presence of serotonin enhances its interaction with postsynaptic receptors, thereby strengthening its overall effect. Common examples of SSRIs include Prozac, Paxil, and Zoloft.

SSRIs and SNRIs

Tricyclic (or heterocyclic) antidepressants inhibit the reuptake of serotonin and/or norepinephrine, and are thus called due to their three (or more)-ring chemical structure. Some examples include:

- Amitriptyline (Elavil) 
- Nortriptyline (Aventyl)
- Maprotiline hydrochloride (Ludiomil)
- Desipramine hydrochloride (Norpramin)
- Clomipramine (Anafranil)

A similar drug is Bupropion (Wellbutrin), which is an aminoketone that weakly blocks norepinephrine, serotonin, and dopamine reuptake.

Tricyclic Antidepressants

MAOIs inhibit the breakdown of the enzyme that breaks down monoamine neurotransmitters. Some MAOIs have antidepressant effects, including:

- Phenelzine (Nardil)
- Isocarboxazid (Marplan)
- Tranylcypromine (Parnate)

Monoamine Oxidase Inhibitors (MAOIs)

Psychedelics, in particular LSD and psilocybin, have been investigated as potential treatments for depressive symptoms. There is evidence for short-, medium-, and long-term usefulness in both micro-dosing and regular studies. In addition to the potential cognitive stimulation (LSD) or emotional well-being effects (psilocybin), these treatments are generally well-tolerated in clinical and general populations. In addition, MDMA has received breakthrough treatment status with the FDA for the treatment of PTSD.

Potential clinical uses for psychedelics

Ketamine, a rapid-acting anesthetic and NMDA receptor antagonist, has been investigated for use in treatment-resistant  depression. When infused in sub-anesthetic doses over a short period (e.g. 40 minutes), ketamine has been shown to have rapid antidepressant effects that can last for up to 4 weeks in some patients.

Using ketamine for treatment-resistant depression

Caffeine has been shown to increase the antidepressant effects of repeated transcranial magnetic stimulation in humans and the antidepressant-like effects of SSRIs, SNRIs, and atypical antipsychotics in mouse models. The proposed mechanism for this is that caffeine's adenosine receptor antagonism increases downstream production of serotonin, dopamine, and norepinephrine.

Learn Before

Related