Outcome studies are inherently flawed. It is easy to ask people questions about subjective experience, give some people a drug (the experimental group), withhold the drug from other people (the control group) and after some period of time ask folks a variety of questions about how they feel.That drugs can positively affect subjective experience is not news.

Granted, tremendous resources have been directed towards control of the use of drugs to alleviate suffering with profound beneficial effects. However, human subjective experience is a profoundly complex phenomenon entirely enmeshed within the context of our lives and hence directly affected by;

• Food products at hand
• Environmental hazards
• Family life
• Larger social, economic and political conditions

An outcome study that factors in that complexity cannot be devised.

Additionally, definitions of what constitutes ‘success’ are inherently problematic:

• Does ‘children behave better in school’ constitute success?
• Does ‘conformity’ constitute success?
• Do reports of preferred states of consciousness constitute success?