Time-dependent sensitization--possible implications for clinical psychopharmacology.

Time-dependent sensitization (TDS) has been described in animal models over the past 20 years. It is a phenomenon that occurs in a variety of biological systems, and corresponds to the cellular and systems response to a foreign or stressful stimulus. The exposure to the stimulus triggers the responses typical of that particular biological system, which are progressively amplified with time. This phenomenon has potential major implications for clinical pharmacology. Some human studies have investigated this phenomenon to date. Antidepressant action, with its typical lag in the onset of effects, may be a fruitful paradigm to understand the relevance of TDS for psychopharmacological treatment. In this paper we review these emerging findings, and suggest that clinical pharmacology research should investigate this process further in expanded human studies.