The paper we discuss is  K Humphreys, JC Blodgett, and TH Wagner. Estimating the Efficacy of Alcoholics Anonymous Without Self-Selection Bias: An Instrumental Variables Re-Analysis of Randomized Clinical Trials. Alcoholism: Clinical and Experimental Research. 2014; 38(11): 2688-2694.

The primary outcomes from Project MATCH, which looked at the efficacy of different psychotherapeutic interventions for alcohol use disorder, can be found here.

Helpful reference on instrumental variables analysis: ML Maciejewski and MA Brookhart. Using Instrumental Variables to Address Bias from Unobserved Confounders. JAMA 2019; 321(21): 2124-2125.

Another example of using instrumental variable analysis to address an important question in psychiatry (this time, related to ECT and hospital re-admission): AT LoSasso. Use of Instrumental Variables Methods in Examining Psychiatric Readmissions. JAMA Psychiatry 2017; 74(8): 805-806.