BACKGROUND: Psychiatric and psychosomatic consultation-liaison services (CL) are important providers of diagnosis and treatment for hospital patients with mental comorbidities and psychological burdens.

OBJECTIVE: To perform a systematic review and meta-analysis investigating the effects of CL on depression and anxiety.

METHODS: Following PRISMA guidelines, a systematic literature search was conducted until 2017. Included were published randomized controlled trials using CL interventions with adults in general hospitals, treatment as usual as control groups, and depression and/or anxiety as outcomes. Risk of bias was assessed using the Cochrane Risk of Bias Tool. Level of integration was assessed using the Standard Framework for Levels of Integrated Healthcare. Meta-analyses were performed using random effects models and meta-regression for moderator effects.

RESULTS: We included 38 studies (9,994 patients). Risk of bias was high in 17, unclear in 15, and low in 6 studies. Studies were grouped by type of intervention: brief interventions tailored to the patients (8), interventions based on specific treatment manuals (19), and integrated, collaborative care (11). Studies showed small to medium effects on depression and anxiety. Meta-analyses for depression yielded a small effect (d = -0.19, 95% CI: -0.30 to -0.09) in manual studies and a small effect (d = -0.33, 95% CI: -0.53 to -0.13) in integrated, collaborative care studies, the latter using mostly active control groups with the possibility of traditional consultation.

CONCLUSIONS: CL can provide a helpful first treatment for symptoms of depression and anxiety. Given that especially depressive symptoms in medically ill patients are long-lasting, the results underline the benefit of integrative approaches that respect the complexity of the illness.