Background: Loneliness-a subjective emotional state characterized by the perception of social isolation-is a psychosocial factor that is associated with increased mortality, substance use, and is associated with precipitants of relapse among individuals with substance use disorders (SUD). Importantly, there are effective interventions that can be used to decrease loneliness; however, these have not been tested on Veterans with SUD who are lonely.

Significance/Impact: Individuals with SUD have higher prevalence of loneliness and loneliness exacerbates pain and sleep disturbance, risk factors of relapse. Without effectively intervening on loneliness, Veterans with SUD will continue to be at high risk of relapse and will maintain problems engaging with social support, including healthcare providers-factors critical for recovery. Cognitive-behavioral therapies (CBT) has shown the strongest effects on loneliness, however, there are no interventions that are specifically designed for substance using populations who are lonely. Testing CBT for loneliness and SUD (CBT-L/SUD) has the potential to have a broad impact on addressing a critical, unmet need that commonly affects Veterans with SUD. The investigators approach of national recruitment and telehealth delivery of this intervention highlights how this this study address VHA care priorities including substance use, access to care, and telehealth.

Innovation: There are no studies that have tested a loneliness intervention in Veterans with SUD who are lonely, which may neglect a broader impact on mental and physical health. This study is ideally situated to generate new and important knowledge on the association of loneliness and SUD. This study seeks to address a transdiagnostic factor, which may improve engagement with social support thereby reducing substance use. An additional innovative aspect of this study is recruitment being conducted outside the VHA. This may increase access to care among those Veterans who are especially isolated.

Specific Aims: the investigators aim to: (1) refine the CBT-L/SUD manual by conducting a one-arm trial among Veterans with a SUD who report loneliness (n = 6), (2) randomize participants to receive either CBT-L/SUD (n = 15) or CBT-SUD (n = 15) to assess feasibility and acceptability among Veterans with a SUD who report loneliness.

Methodology: the investigators will elicit feedback on a draft of the CBT-L/SUD manual then conduct a small single-arm trial (n = 6) for further refinement. Specifically, SUD treatment providers and Veterans with SUD will provide feedback on the draft manual, which the research team will integrate to finalize the manual for a small single-arm trial. This trial will allow us to collect feasibility of treatment delivery, and treatment satisfaction and acceptability data to further refine the manual. With the refined manual Veterans with SUD reporting loneliness will be randomized to either CBT-L/SUD (n = 15) or CBT-SUD (n = 15). The investigators will assess: (1) treatment acceptability, (2) participant adherence to treatment, and (3) therapist fidelity. The investigators will also assess outcome measure completion percentage, means and standard deviations, and level of correlation of repeated measurement of primary loneliness outcomes and secondary substance use outcomes.

Implementation/Next Steps: Results from this study will provide critical feasibility and acceptability data to inform an HSR&D Merit Award application to conduct a fully-powered randomized controlled trial. The research team will work with the VA Office of Mental Health and Suicide Prevention and the Substance Use Disorder office of the National Mental Health Program to identify implementation and dissemination efforts. For example, the investigators plan to translate findings into applied practice across various settings (e.g., primary care mental health, rehabilitation treatment programs). Additionally, this intervention may be particularly useful for behavioral telehealth centers that deliver evidence-based interventions to rural and other Veterans who have difficulty accessing VHA care.

Inclusion Criteria:

• Participants must be ages 18+,
• understand English,
• have access to a phone or computer,
• screen positive for an active, at least moderate SUD. SUD include alcohol, marijuana, opioids, cocaine, other psychomotor stimulants (methamphetamine, amphetamines), and sedative/hypnotic/anxiolytic use disorders.
• Participants will need to screen positive for loneliness.

Exclusion Criteria:

• Participant with significant cognitive impairment will be excluded.

from enrollment until end of follow-up (baseline assessment, post-treatment assessment, 1-month follow-up; 8 intervention session; ~3 months)

The outcomes assessors will not know what condition that the participant was allocated to, nor will the statistician who is one of the co-investigators.