Epidemiological data show pronounced gender differences in the prevalence of substance use disorders (alcohol, sedatives, opioids, nicotine, psychostimulants, cannabinoids). Social, psychological and biological including genetic factors contribute to the gender differences. Several studies show in men a higher participation of genetic factors in the development of an addiction disease than in women, in which besides genetic factors other factors seem to be more prominent. The occurrence of psychic dependence with drug seeking behaviour is the outcome of a number of variables including sex hormonal, neuronal (dopamine and interactive transmitters f.e glutamate, GABA, serotonine, opioid peptides), genetic, developmental, age, neurodegenerative and environmental elements that interact to produce profound individual (gender) differences in both initial and longterm responsiveness to addictive drugs. Sex steroids, especially estrogens, are responsible for the synthesis and secretion of neuropeptides (eg opioids peptides), but also of the neurotransmitters dopamine, serotonine etc and may exert by these mechanisms and environmental interaction gender effects in addiction diseases. The diverse factors also have a significant impact on the accessibility to and effectiveness of pharmacological and psychotherapeutic treatment of different substance disorders in women and men.

Single representive results from animal and clinical studies especially on individual (genetic, sex hormonal, gender identification) differences will be presented which focus on key issues which may improve treatment effectiveness and models of service provision.