[Hard use of soft drugs]

The concept of "soft drugs" is unclear and refers more to the behaviour of consumers than to the specific pharmacological properties of substances. However, "soft drugs" is often understood as "safe drugs." However, it is of major importance to underline that all drugs can induce major loss of the control of consumption, what is the crucial point of addictive behaviour. This is due to a sensitization of the so-called" brain reward system"; moreover, there is cross-sensitization between drugs. Only cannabis and alcohol are frequently thought to be associated to a long-term safe consumption. In our experience, this reputation is broadly usurped. Indeed, we observed that even when they do not have major health problems, cannabis consumers present major alterations of social functioning. In another way, we have shown that heavy alcohol consumers without neurological complications have frequently frontal dysfunction, clinically correlated to major alterations of executive functions.