Objective. In the field of mental health care, a major role for general practice is advocated. However, not much is known about the treatment and referral of mental health problems in general practice. This study aims at the volume and nature of treatment of mental health problems in general practice; the degree to which treatment varies according to patients' gender, age, and social economic status; and trends in treatment and referral between 2004 and 2008. Design/setting. Descriptive study with trends in time in general practice in the Netherlands. Subjects. 350,000 patients enlisted in general practice, whose data from the Netherlands Information Network of General Practice were routinely collected from 1 January 2004 to 31 December 2008. Main outcome measures. For all episodes of mental health problems recorded by the GP, the proportion of patients receiving prolonged attention, medication, and referral during each year have been calculated. Results. More than 75% of patients with a recorded mental health problem received some kind of treatment, most often medication. In 15-20% of cases medication was accompanied by prolonged attention; 9-13% of these patients were referred (given referrals), the majority to specialized mental health care. Age is the most important variable associated with treatment received. During the period 2004-2008, treatment with medication declined slightly and referrals increased slightly. Conclusion. Treatment for psychological disorders is mostly delivered in general practice. Although in recent years restraint has been advocated in prescribing medication and collaboration between primary and secondary care has been recommended, these recommendations are only partially reflected in the treatment provided.