[Cannabinoid drugs for neurological diseases: what is behind?]

In recent years progress has been made in the development of pharmaceuticals based on the plant Cannabis sativa or on synthetic molecules with a similar action. Some of these pharmaceuticals, such as the mouth spray Sativex, have recently been approved for the treatment of spasticity in multiple sclerosis, but they are not the first and others, such as Marinol or Cesamet for the treatment of vomiting and nausea, and anorexia-cachexia syndrome, had already been approved. This incipient clinical use of cannabinoid drugs confirms something that was already known from fairly ancient times up to practically the last century, which is the potential use of this plant for medicinal applications - something which was brought to a standstill by the abusive use of preparations of the plant for recreational purposes. In any case, this incipient clinical use of cannabinoid drugs is not backed just by the anecdote of the medicinal use of cannabis since ancient times, but instead the boost it has been given by scientific research, which has made it possible to identify the target molecules that are activated or inhibited by these substances. These targets are part of a new system of intercellular communication that is especially active in the central nervous system, which is called the 'endogenous cannabinoid system' and, like many other systems, can be manipulated pharmacologically. The aim of this review is to probe further into the scientific knowledge about this system generated in the last few years, as a necessary step to justify the development of pharmaceuticals based on its activation or inhibition and which can be useful in different neurological diseases.