The announcement Tuesday that Lake Shore Behavioral Health with Child & Adolescent Treatment Services will be partnering as a single entity continues a trend in the nonprofit sector. Scale has been cited by several nonprofits in recent local mergers, including Suburban Adult Services Inc. and Claddagh Commission in Derby, which completed a merger in January; while financial distress was the impetus between a merger last year between Fellowship House of Niagara Falls and Buffalo-based Cazenovia Recovery…