F.Kiss - I am not sure what you were told, but serotonin syndrome is not a disorder, like hypertension or depression, but usually results from a drug-drug interaction (either a pharmacokinetic or pharmacodynamic interaction between the drugs) between drugs that increase serotonin concentrations in the body. Serotonin syndrome commonly occurs when two serotonergic antidepressants with different mechanisms of action are taken together. For example, when a monoamine oxidase inhibitor (MAOI: eg. Parnate™ - tranylcypromine) is taken with a selective serotonin reuptake inhibitor (SSRI: Prozac™ - fluoxetine).

Serotonin syndrome is characterized by changes in autonomic nervous system, neuromotor, and cognitive-behavioral function. These changes manifest as the following symptoms:

An overactive autonomic nervous system results in excessive sweating (diaphoresis), increased body temperature (hyperthermia), increased blood pressure (hypertension), a rapid heartbeat (tachycardia), dilated pupils, shivering, nausea, and
diarrhea.

Overactive motor nerves result in hyperreflexia, involuntary muscle twitching and spasming of skeletal muscles (clonus) or groups of muscles (myoclonus), restlessness, tremor, a lack of coordination, rigidity, teeth chattering (or shivering), lockjaw (trismus), and seizures.

Cognitive-behavioral effects of serotonin syndrome include: confusion, agitation, anxiety, hypomania, insomnia, hallucinations, and headache.

Rarely serotnin syndrome can result in severe hyperthermia (increased body temperature) with complications such as disseminated intravascular coagulation (blood clotting throughout the body), rhabdomyolysis (breakdown of skeletal muscle), renal failure, coma, and death.

I have not heard of stuttering, depressive episodes, screaming or crying as a direct result of serotonin syndrome. While some people may be genetically sensitive to the effects of serotonin (and thus serotonergic agents), I have not heard of anyone who spontaneously acquired serotonin syndrome with no causative agent (eg. the ingestion of a serotonergic substance). I doubt that serotonin syndrome can be caused psychologically.

I hope that this is of some help. - Cam