Private equity firm Nautic Partners LLC has acquired QoL Meds LLC. 

QoL, headquartered in Pittsburgh, is a pharmacy that provides mental health medication. In the past five years the company has expanded its number of pharmacies from two to 87. Terms of the deal were not disclosed.

"The market for mental health services is large and growing," says Nautic principal Chris Corey. 

Providence-based Nautic has made many investments in the health care industry, including American Imaging Management, Axia Health Management and Genova Diagnostics, which Nautic sold to Levine Leichtman Capital Partners in November. 

The firm picked up QoL from its sixth fund, Nautic Partners VI LP. Nautic has about $2.5 billion in capital under management, and targets investments between $25 million and $75 million. In July, Nautic bought pipeline inspection group Applied Consultants Inc.