Measuring motivation in people with schizophrenia.

Motivational deficits are a key determinant of poor functional outcomes in schizophrenia. These impairments are typically evaluated using various clinical rating scales; however, the degree of convergence between motivation scores derived from different instruments is not clear. In the present study, we measured motivational deficits in 62 patients with schizophrenia using 5 scores derived from 3 different instruments. We found that the scores from these different instruments were highly inter-correlated, and largely independent of severity of other symptom domains (e.g., depression). Our findings suggest that clinical ratings scales evaluating motivational deficits are tapping into a similar underlying construct.