Methods: A systematic online and manual reference list search was conducted for studies meeting these inclusion criteria: published 1995-2009, evaluated an empirical intervention for SOs, described the above outcomes as reported by SOs. Each study was rated on methodological rigor using a modified Methodological Quality Rating Scale. Studies were separated into lower and higher methodological quality using a median split of the total scale scores. Reported outcomes were evaluated in light of the quality of the study and the purpose of intervention (coping skills training for SO [CST], teaching SO how to encourage PA to enter treatment [EPA], or SO participation in PA addiction treatment [AT]).
Results: The search yielded 29 studies meeting inclusion criteria: thirteen CST, seven EPA, and nine AT studies. CST interventions were effective in reducing psychiatric distress and enhancing coping skills, whereas AT interventions were more effective in improving family relationships. Only one study reported a reduction in family conflict/violence. Over half of the CST (58%) and AT studies (67%) were of higher quality, but 71% of the EPA studies were of lower quality. Lower quality studies were more likely than higher quality studies to utilize shorter follow-ups and to have small sample sizes, with resulting power and statistical analysis shortcomings. Studies focused on SOs of PAs with alcohol use (17 studies), drug/alcohol use (8 studies), or gambling (4 studies) disorders, but results did not differ by addiction.
Conclusions and Implications: Evidence from the last 14 years indicates that both CST and AT programs are effective in improving outcomes for SOs. PA programs should include SOs wherever possible, as relationship benefits occur when addiction treatment includes a focus on the couple. Moreover, CST interventions should be available to reduce the burden of addictions on SOs even if the PA does not want to enter treatment. Although the EPA interventions showed fewer positive outcomes than did CST or AT studies, due to low power in these studies this result must be considered tentative.