Alla ricerca di fattori patogenetici comuni tra dipendenze e disturbi mentali: disedonia e comorbidità psichiatrica
Year: 2006
Type: article
Abstract: Summary Objective Drinking, lating, sexual and maternal behaviour are directed towards objects essential for survival of the self and of the species. Natural selection, in order to ensure the fulfilment of these behaviours, has provided these objects with powerful rewarding properties. The evidence showing that stimulation of dopaminergic transmission in the mesocortico-limbic system relates to the rewarding proprierties of drugs of abuse brings one to ask what is the significance of the drug-induced changes on this neural pathway. In answering this question one should consider that drugs act on the biological organism to the extent that they are able to activate biological processes, which are operative independently of the drug itself. Drugs do not invent anything new but just mimic or interfere with what is preformed. This consideration also applies to drugs of abuse; thus drugs owe their abuse liability to the fact that they activate the neural pathways which carry natural rewarding stimuli. The objective of the present paper was to search any common pathogenetic factor between addictions and mental disorders. Methods Evidence from literature was reviewed regarding different therapeutic objectives between different substance-related, psychiatric comorbidity and their pathogenetic correlates. Results The onset of a drug addiction and the vulnerability to relapse, after abstinence, can be related to complex neuro-adaptative brain processes. The meso-cortico-limbic dopamine system arises from perikarya in the ventro-medial mesencephalon and innervates a number of cortical and limbic regions. A number of studies confirm a relevant role of this system in reward processes and drug addiction, including sensitization to psychostimulant drugs. The long-lasting actions of drugs of abuse lead to impairment in the rewarding mechanisms, but also affective symptoms such as anxiety, dysphoria and depression. In the last few years, the role and the function of this system in the pathophysiology of certain neuropsychiatric disorders has been postulated. Some studies support the possibility that different psychotic (including schizophrenia) and non-psychotic disorders may result from a deficit of dopaminergic transmission in the prefrontal cortex. In the last few years, the attention of many researchers and clinicians has focused on psychiatric comorbidity in alcohol-substance abusers, in the light of the self-medication hypothesis of addictive disorders, but also as an expression of a specific psycho-biological vulnerability. Conclusions A growing body of evidence suggests a dysregulation of the homeostatic hedonic control system as a common factor in the development of drug addiction and vulnerability in relapse following withdrawal. It is evident that the “hedonic homeostatic dysregulation” can be evaluated not simply in terms of presence or absence of pleasure capability, but also in terms of qualitative and quantitative differences from the normal conditions. The hedonic homeostatic dysregulation (dyshedonia), functionally related to the meso-cortico-limbic control of the rewarding functions, could be pathogenetically related, not only to drug addictions, but also to some other psychiatric disorders, with or without addictive features. This paper attempts to conceptualise addiction and other mental disorders as distinct psycho-pathological entities (nosographic categories) with common pathogenetic factors, as dyshedonia, from a transnosographic and dimensional point of view.
Author: Vincenzo Manna
Language: Italian
Subfield: Cellular and Molecular Neuroscience
Field: Neuroscience
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W2182228177