Opioids and anxiety

Abstract

The opioid system plays a crucial role in the neural modulation of anxiety. The involvement of opioid ligands and receptors in physiological and dysfunctional forms of anxiety is supported by findings from a wide range of preclinical and clinical studies, including clinical trials, experimental research, and neuroimaging, genetic, and epidemiological data. In this review we provide a summary of studies from a variety of research disciplines to elucidate the role of the opioid system in the neurobiology of anxiety. First, we report data from preclinical studies using animal models to examine the modulatory role of central opioid system on defensive responses conducive to fear and anxiety. Second, we summarize the human literature providing evidence that clinical and experimental human studies are consistent with preclinical models. The implication of these data is that activation of the opioid system leads to anxiolytic responses both in healthy subjects and in patients suffering from anxiety disorders. The role of opioids in suppressing anxiety may serve as an adaptive mechanism, collocated in the general framework of opioid neurotransmission blunting acute negative and distressing affective responses.

Evaluation of different procedure involved in the Transcranial Direct Current Stimulation (tDCS) technique experimental application

“…Indeed, chronic stress is associated with increased sensitivity to pain, producing hyperalgesia 19,22,43,44 , and allodynia 19,43 . It is known that stress situations can activate the endogenous opioid system and promote behavioral changes, such as diminished anxiety levels, a protective mechanism of body resistance to stress 45 . Furthermore, a human study has shown that a reduction in pain threshold after long-term psycho-emotional stress probably occurs due to a decrease in the activity of the brain's opioid system 46 .…”

The anxiolytic-like activity of a novel N-cycloalkyl-N-benzoylpiperazine derivative

“…Since accumulating data indicate that the opioid system might play 48 a crucial role in the neural modulation of anxiety, and the 49 activation of the opioid system leads to anxiolytic responses both 50 in healthy subjects and in patients suffering from anxiety disorders 51 [11], the potential anxiolytic-like properties of compound 9 used 52 both alone or after the pretreatment with an opioid receptor 53…”

Posttraumatic and depressive symptoms in β-endorphin dynamics

“…This hormone is involved in affect, memory, cognition, reward, immunity, respiration, to name just a few systems in which the role of β-endorphin is still being investigated. Its "multitasking" relates β-endorphin to many forms of behavior/symptoms, such as anxiety (Colasanti et al, 2011), anger control (Bruehl, 2009) and aggression (Roubertoux et al, 2005), depression (Hegadoren et al, 2009), addictions (Barry, 2012), etc.…”