The cocaine experience: refuting the concept of a model psychosis?

Eighteen patients admitted to a drug dependency unit for opiate detoxification and who had recently used cocaine were asked to describe the experience based on a questionnaire. A comparison was made with 18 schizophrenic patients who completed the same questionnaire. Results showed a qualitative difference in the subjective phenomena described by the two groups. There appeared to be certain phenomena present in a cocaine induced state which appear to be specific to this state. Amongst these features are: increased intensity of colours, prominence of certain colours in illusions, i.e. red and green, and changes in light intensity. Objects appear to be more vivid and stand out, macropsia and micropsia also seem to occur in this group and paranoia if present is of a transient nature. These particular symptoms do not seem to be characteristic of a schizophrenic illness. This may therefore contradict the idea of a drug induced psychosis (in this case cocaine) as being indistinguishable from schizophrenia (the model psychosis theory).