Computerised measurement of reaction times is state of the art in many fields of research and clinical examinations. Usually, these examinations employ only measures of central tendency (median, mean), deviation (standard deviation) and correct reactions (false reactions). The time course (i.e., sequence) of the individual reaction times has hardly been considered so far.

Using an assessment software recently developed for scientific purposes (Procalysis®)the attentional performances of multiple drug users are assessed in the context of time series analyses regarding specific effects of comorbidity (e.g. schizophrenia) or the respective drug use profile.

In addition to the main affects of multiple drug abuse, comorbid schizophrenia is another significant cause of fluctuating reaction times. Besides generally reduced mean reaction times, the time course analyses also indicate comorbidity-dependent specific stage characteristics, which in turn are related to task complexity.

Both in research and the clinic, time series analysis of reaction times should be considered. They can help reveal stage characteristics over time, which can give the clearest indication yet of the extent of subtle brain dysfunctions. This also applies to the ecological validity of single case assessments, such as for determining the ability to drive or operate machinery.