Recent epidemiological surveys that have attempted to include the need for treatment of mental disorders are reviewed, and it is concluded that the greatest unmet need is for those with non-psychotic disorders. Recent studies on factors that influence the natural history of such disorders reveal that these are largely social and environmental; one study suggests that genetic factors are only important in the group that have longer time courses. Those factors within the medical encounter that produce better outcomes are reviewed, and non-specific factors and supportive therapy are found to be important. Some additional advantages are to be obtained with specific antidepressant treatments (either pharmacological or problem-solving) and with re-attribution skills for psychologically determined somatic symptoms. The implications of these findings are discussed from the standpoint of the primary care team, the community mental health team and self-help materials.