The prodrome corresponds to a particular symptom since it signs the onset of a disease, generally announcing an acute phase of it.

The prodromal state is more often called the prodromal phase in medicine, and refers to a period during which a set of symptoms will be observed, often mild, but revealing the arrival of the acute phase of a disease, or main phase.

The example that comes up often enough to illustrate the prodromal state is the disease of schizophrenia. This Psychiatric illness is characterized by a set of highly variable symptoms: delusions and hallucinations, social withdrawal and cognitive difficulties. Usually developing in adulthood, this disease can show warning signs during the teenage years of the subject. Symptoms of the prodromal phase are:

• lack of concentration;
• irritability, unwarranted anxiety;
• social isolation;
• general carelessness;
• depressive tendency;
• recurrent fatigue for no apparent reason.

At this stage, the adolescent is not psychotic, but these warning signals can alert him to his state of becoming.

This prodromal phase is found in 80 to 90% of patients with schizophrenia. It can last for five years, and its symptoms gradually set in, going from moderate to weak intensity to more intense. However, these prodromal symptoms are not necessarily specific to schizophrenia, and can also cause the patient to progress to another mental pathology.

Other diseases have a prodromal phase:

• syphilis: prodromal symptoms are an inoculation chancre and skin rashes;
• AIDS: prodromal symptoms are flu-like symptoms, fever, headache, asthenia, diarrhea;
• acute radiation syndrome: prodromal symptoms are fatigue, nausea, vomiting, within two days of exposure to ionizing radiation.

The prodromal phase occurs due to the onset some time later (days, months, or years depending on the disease) of a disease. The arrival of this disease can have several causes. For schizophrenia, there may be a genetic background conducive to the onset of this disease, or stress factors linked to the environment.

Schizophrenia, difficult to diagnose, begins following an inaugural psychotic episode, not always identified or managed. Evolving in a fluctuating manner, it presents chronic symptoms, with acute phases. Symptoms stabilize as well. But this evolution therefore depends on the precocity with which the disease was treated, and therefore whether a doctor was alerted as soon as the prodromal symptoms arrived.

For AIDS, the prodromal phase occurs shortly after being infected through sex or blood. Likewise with this disease, the effects and severity of symptoms can be reduced if the disease is detected at the prodromal stage.

Symptoms that are generally not very alarming, but which may raise questions for those around them and the patient himself, will thus be observed on the subject. In the case of schizophrenia, the prodromal phase settling in at the age of adolescence or young adulthood, the entourage and parents may feel real discomfort when they notice the symptoms (depressive tendency, social isolation, lack of ability to concentrate), and declare that they no longer recognize their child or their friend.

It can be much more beneficial to alert your doctor as soon as you notice the arrival of these warning signs, since a disease that is detected earlier can be better treated and the patient better taken care of than if the pathology appears late.

Despite this, it is difficult or almost impossible to prevent the disease from setting in then, when prodromal symptoms are present. However, intervening as early as possible will often limit the disorders linked to the disease and allow more effective treatment.

As has been pointed out previously, the fact of detecting prodromal symptoms as early as possible allows the medical profession to intervene earlier in order to better treat the disease. With regard to schizophrenia, appropriate management, combining pharmacological and psychosocial treatment, makes it possible to obtain long-term remission in more than a third of patients.

Doctors and medical researchers are still trying to identify the warning signs of this disease today in order to be able to intervene as soon as possible and reduce the severity of the pathology.

For other pathologies having a prodromal phase, the principle of intervening as soon as possible is the same: the objective being to prevent the severity of the symptoms of the main phase of each disease.