Chronic cannabis users: Further analysis of objective test results

Twelve objective tests, generating 16 psychological test variables were administered to 850 chronic cannabis takers and 839 non-takers, all Egyptian males, ranging in age between 15 and 50 years, and representing various positions on continua of literacy-illiteracy and urbanism-ruralism. The tests were intended to assess different modalities of 5 broad psychological functions: speed of psychomotor performance, estimation of moderate distances, estimation of a few minutes time interval, immediate memory for digits and designs and visual-motor co-ordination. Analysis of variance based on 3 x 3 x 2 factorial design was carried out and revealed statistically significant differences between the two groups of subjects on most of the test variables. Detailed analyses showed that controls displayed better performance than drug users on the majority of the variables. Significant second order interaction effects emerged in a big number of cases denoting that, under certain conditions relating to literacy-illiteracy and urbanism-ruralism, the superiority of controls over cannabis users became much more impressive. Our findings were discussed in the light of investigations which were conducted on the psychological correlates and/or effects of long term and short term cannabis consumption. The clinical psychological literature was cited where slowness of psychomotor performance, defective visual-motor co-ordination and impaired memory for designs were reported to be associated with psychiatric disorder. It is suggested that our results point to meaningful associations between chronic cannabis consumption and manifestations of psychopathology.