Systematic review of mental or behavioral health care in integrated specialty medical care settings.

INTRODUCTION: Although the integration of mental health services is widely accepted as important in primary care, the benefits for specialty medical care are less clear. This systematic review aimed to assess evidence on whether mental or behavioral health integration into specialty care can improve patient and health service delivery outcomes. METHODS: We searched MEDLINE and APA PsycInfo from 2014 to 2024. We also hand-searched reference lists, consulted content experts, and used an artificial intelligence function (DistillerSR). Studies were included if they met the following criteria: (a) adult patients in specialty medical care with co-occurring behavioral health conditions; (b) use of approaches or models for integration of mental/behavioral health; (c) comparison with usual care or alternative approaches; and (d) reporting patient and health service delivery outcomes. RESULTS: We reviewed 39 studies (out of 6,392 identified titles), yielding 17 original research articles (describing 15 integrations). Based on the Center for Integrated Health Solutions framework, we found only one published study describing full collaboration in an integrated practice (Level 6). We assessed one study at Level 5, seven studies at Level 4, five studies at Level 3, and one study at Level 2. Outcomes of interest and intervention characteristics varied greatly across studies, making it difficult to draw comparisons. DISCUSSION: There is insufficient evidence from the published literature on how best to integrate mental/behavioral health services into specialty care. Additional research remains necessary to confirm any promising early findings. Future studies could be strengthened by aligning outcomes and providing more detail on integration processes. (PsycInfo Database Record (c) 2026 APA, all rights reserved).