Patients with many problems often face difficulties in modifying their behavior as desired. Uncovered basic needs may be an important barrier. This research tests the effect of patient-centered consultations for 20- to 44-year-old patients with multiple psychosocial and lifestyle problems. We focus on resources and barriers for obtaining self-chosen goals within life circumstances and lifestyle. At 28 general practitioners, 2056 patients aged 20-44 years were screened with a 33-item problem-score on resources, network, lifestyle and social conditions. The 30% who had most problems were invited to complete a more comprehensive questionnaire at home. Intervention was preventive consultation with a 3-month follow-up. A total of 495 patients were randomized. One-year questionnaire follow-up showed significant improvement in Short Form Health-related Quality of Life Mental (MCS-SF12) in the intervention group (7.3) compared with the control group (3.0); the difference was 4.3 (95% confidence interval 1.6-7.0, P = 0.002). The number of problems was reduced significantly more in the intervention than in the control group (1.8 versus 0.8, P = 0.03). Preventive consultation focusing on resources and barriers to self-chosen goals may improve MCS-SF12 and decrease the number of problems in patients with many psychosocial and lifestyle problems. This may be an indicator of improved specific self-efficacy and a key to lifestyle changes.