It is necessary that molecular weight calculator appropriate time for this training be considered and also teachers must abide the principles of adult education. If the class time can be set such that learners could more easily participate in it, class performance and learners eagerness will be increase. Acknowledgments We wish to thank all those helped us in doing this research, especially Rebirth Society managers and staff, rehabilitation centers, professors and graduates of chemical dependency counseling course and finally Mr Omid Setudeh and Mrs Sedigheh Kavand. Footnotes Conflicts of Interest The Authors have no conflict of interest.
Addiction toward natural and artificial substances has increased during the past few decades which indicates the incidence of a new problem in physical and social health.

1 The term addicted individual can be defined as one who has a very strong desire toward addictive substances, regardless of its consequences.2 According to the UNODC (United Nations Office on Drugs and Crime), 172-250 million people in the world have used illegal drugs at least once a year3 and according to the latest reports in the rapid situation assessment (RSA) of drug abuse in Iran, the number of addicts are estimated to have been 1,200,000 people in 2007.4 On the other hand, statistics indicate that the drug use rate among different communities particularly among youths and adolescents has had an increasing growth in the recent decade.5 Scientifically, tendency to addiction is an internal state in which there is a high likelihood of addiction.

6 Factors influencing the tendency of youths towards addiction are personal, interpersonal and social factors. Anxiety and depression (mental factor) are two of the high risk personal factors.7 Some studies have indicated that personal factors, anxiety and depression are the most important causes of the tendency to addiction.8 Many studies have emphasized the prevalence of psychiatric disorders such as anxiety and depression among substance users.9,10 The findings indicated that depression can occur during substance using and/or after withdrawal. Thus, data show that more than 37% of alcohol abusers and 53% of drug abusers at least suffer from one serious psychological disease. On the other hand, depression, anxiety and other psychological disorders also increase the risk of addiction; given that statistics show 29% of those with one type of psychological disease also suffered from either alcohol or other illegal drugs abuse.

9 One of the explanatory models of mood disorders, such as depression and anxiety, is the metacognitive model which Carfilzomib is a multi-dimensional concept. It includes knowledge, processes and strategies that recognize, assess or control cognition.11 Self-regulatory executive function (S-REF) Model by Matthews is the first theory conceptualize the role of metacognition in etiology and continuation of psychological disorders.