Abstract

Can there be scientific theories in psychology, medicine or psychiatry? I approach this question through an in-depth analysis of a typical experiment for clinical depression involving the monoamine hypothesis, drug action, and placebos. I begin my discussion with a reconstruction of Adolph Grünbaum's conceptual analysis of 'placebo,' and then use his notion of "intentional placebo" to discuss a typical experiment using the monoamine hypothesis, two drugs and a placebo. I focus on the theoretical aspects of the experiment, especially on the notion of causal explanation. I then raise five conceptual and methodological problems for theory construction. These problems focus on questions of the causal efficacy of placebos and drugs; ad hoc versus ceteris paribus explanations in biomedicine and psychology; and the falsifiability of the monoamine hypothesis. I conclude by pointing out the need for further, rigorous philosophical analysis concerning the possibility of theory construction in psychology, medicine, or psychiatry.