This study demonstrates the efficacy of Self-Regulation Therapy (SRT) to induce effects of cocaine and speed in a single session. SRT is a suggestion procedure of sensorial recall exercises (salivation, feeling of weight, tension, etc.) that increases the capacity to reproduce all sensation types and those that drugs produce. The Self-Regulation Scale (SRS) measures this capacity. Four groups participated, formed according to drug use: Group 1 (uses no illegal drugs); Group 2 (experimentally uses cannabis only); Group 3 (moderate drug users); Group 4 (regular drug users, especially stimulants). All four groups participated in an SRT session to induce relaxation. No differences in the SRS were found. Group 4 also participated in a session that reproduced effects of drugs with SRT, when Euphoria and the Effects of drugs score (high and rush) substantially increased in relation to the base-line (MD = –5.83; p < .001; and MD = -3; p < .001, respectively) and in relation to the relaxation session (MD = –4.06; p < .001; and MD = -1.96; p < .05, respectively). A profile predicting SRT efficacy was also obtained to induce the effects of cocaine and speed: low Conscientiousness and high Openness and SRS scores. Finally, the potential use of this procedure to treat addictions, and strategy development towards more controlled, responsible drug use, are discussed.

A deepening in the biological nature of the general factor of personality (GFP) is suggested: the activation level of the stress system is here represented by the gene expression of c-fos. The results of a single case experimental design are reported. A model of four coupled differential equations that explains the human personality dynamics as a consequence of a single stimulant drug intake has been fitted to psychological and biological experimental data. The stimulant-drug conditioning and its adaptation to the considered mathematical model is also studied for both kinds of measures. The dynamics of the c-fos expression presents a similar pattern to the dynamics of the psychological measures of personality assessed by the GFP-FAS (Five-Adjective Scale of the General Factor of Personality) as a consequence of a single dose of stimulant drug (methylphenidate). The model predicts similar dynamic patterns for both psychological and biological measures. This study proves that describing mathematically the dynamics of the effects of a stimulant drug as well as the effects of a conditioning method on psychological or subjective variables and on gene expression is possible. It verifies the existence of biological mechanisms underlying the dynamics of the General Factor of Personality (GFP).