This study is a pragmatic randomized controlled trial (RCT) evaluating the effect of brief versus short psychotherapy in subjects with substantial mental complaints.

Running evaluations of the brief intervention (BI) at our outpatient clinic preceding to this study had given us the impression that the patients obtained a more active coping style towards their health problems with consequential enhanced work participation (WP). These evaluations, in addition to our experiences in BI for low back pain (LBP) has generated the current hypothesis of this study towards WP. Yet, the sustainability of WP and long-term effects on mental health remained questionable. In this pragmatic RCT the objective was to compare brief psychotherapy with focus on normalization and coping (Brief-PsT) with short-term psychotherapy of standard duration with more extended focus (Short-PsT), as otherwise used at the Mental Health services. The primary aim of this study was to assess differences in effect on WP and the secondary aim was to assess differences in clinical response. The investigators hypothesized that in the short term, Brief-PsT could facilitate or sustain WP in a superior fashion to Short-PsT in persons who are on, or at risk of sick leave due to mental health problems. Although the investigators expected a substantial long-term rate of clinical recovery and reduction in mental health-related symptoms in both groups, the investigators had no specific hypothesis regarding the extent and direction of possible group differences in these clinical measurements.

Inclusion Criteria:

• 'mental complaints' was the main reason for referral to the outpatient clinic
• employed and on or at risk of sick leave

Exclusion Criteria:

• acute or severe pathology that required greater input than the clinic could offer,
• Sick-leave had > 9 months during the preceding 2 years

Outcome assessor of primary outcome (sickness benefit) is masked for intervention allocation. Other outcome measures are assessed by patient questionnaires.