Receptor Sensitivity and the Mechanism of Action of Antidepressant Treatment

Antidepressants and biochemical theories of depression.

“…This suggests that α-adrenergic postsynaptic receptor sensitivity is increased after long-term treatment. This finding is consistent with other physiological studies discussed previously that found an increase in sensitivity in postsynaptic α-receptors with chronic treatments (Charney et al, 1981).…”

Neutrophil β 2 -adrenergic receptor coupling efficiency to Gs protein in subjects with post-traumatic stress disorder and normal controls

“…Increased AR density and supercoupling in PTSD may be consistent with reported mechanisms of action of antidepressants, which downregulate AR density, particularly in the high-conformational state, induce AR uncoupling and decrease cAMP responses (Banerjee et al 1977;Sulser 1979;Sulser et al 1984;Charney et al 1981;Hancock and Marsh 1985;Okada et al 1986;Manier et al 1987;Tsuchiya et al 1988). The present findings may underlie the partial efficacy of antidepressants, particularly tricyclics and monoamine oxidase inhibitors, in the treatment of PTSD, which have been shown to improve not only anxiety and depressive symptoms, but also PTSD-specific symptomatology (for review, see Southwick et al 1994).…”

Long-Term Effects of Alprazolam and Imipramine on Cerebrospinal Fluid Monoamine Metabolites and Neuropeptides in Panic Disorder

“…Previous studies on CSF monoamine metabolites have produced conflicting results in affective disorders [19,20], While the early studies suggested low MHPG and 5-HIAA values in the CSF of depressed patients, these findings have been difficult to confirm later [21], Also in our panic patients, no clear-cut relationship was found between total scores for the depression and base line CSF metabolite levels studied. Obsessive-compul sive disorder (OCD), like panic disorder, is characterized by coexisting symptoms of depressive illness, but similar studies in OCD have been contradictory showing both decreased and increased 5-HIAA levels in CSF [22].…”

“…There is evidence that tricyclic antidepressants re duce the turnover of monoamines, which in turn causes a reduction in the respective metabolite levels in CSF [20]. In the present study, imipramine consistently seemed to reduce CSF MHPG (14%) and 5-HIAA (17%) levels.…”