The Measurement of Retardation in Depression

The description of clinical features helps to distinguish between depressive illness andnondepressive psychic pain and enables the clinician to decide whether prescription of an antidepressantis beneficial. Psychomotor retardation is probably a central feature of depression, and this reviewdiscusses the methods available for measuring it. The Salpêtrière Retardation Rating Scale (SRRS)specifically measures psychomotor retardation; the scale and applications are described. Means ofmeasuring motor and speech activity and an experimental approach for understanding the process underlyingpsychomotor retardation are reviewed. Comparison of the SRRS and other rating scalescores demonstrates that retardation is related to depression severity and therapeutic change and is agood criterion for prediction of therapeutic effect. The SRRS has been used to show that selective antidepressantstarget specific clinical dimensions of depression depending on the patient subgrouptreated. Measures of motor and speech activity are sensitive to therapeutic response. Choice ReactionTime and Simple Reaction Time tasks are particularly suited for examining psychomotor retardationbecause they test the decision process while avoiding motivation and attention interference. Psychomotorretardation is a constant and probably central feature of depression. Means available formeasuring it can be used to assess the effects of antidepressants on specific clinical dimensions.