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Heroin Addiction and Related Clinical Problems: 2013, 15, 3 (pages: 35 - 46)

Psychosis, trauma, and opioid hypoactivity in the thalamus: a hypothesis

Vukadinovic Z.

Summary: There is a considerable overlap between opioid dependence, psychosis and trauma. This review article presents a neurobiological model that links these related clinical issues and centers on the role of the thalamus. Namely, one of the major roles of the thalamus is that of a hub for cortico-cortical interactions. Such interactions enable the recognition of self-initiated actions. Impairments in trans-thalamic cortico-cortical interactions may underpin psychosis by a mechanism whereby self-initiated actions are not recognized as such and are experienced as if they originate from outside of oneself. Impairments in trans-thalamic cortico-cortical communication could occur secondary to deficits in thalamic neuromodulatory mechanisms, including the endogenous opioid system. Indeed, there is evidence that in some individuals with an underlying genetic vulnerability to psychosis, exposure to stress may lead to endogenous opioidergic hypofunction in the thalamus, which could in turn be related to the emergence of psychosis and opioid dependence in such individuals. This scenario could account for reported antipsychotic efficacy of opioid agonist in some individuals with co-occurring psychosis and opioid dependence.