Early rehabilitation for critically ill adult patients: protocol for an umbrella review.

Suicidal thoughts and behaviors (STBs), including suicidal ideation (SI), suicide attempts (SA), and non-suicidal self-injury (NSSI), are a significant and growing public health concern among young adults in the United States (US). Suicide is the second leading cause of death among individuals ages 10–34 years (). Rates of SI, SA, and NSSI have increased substantially over the past two decades. Data from the National Survey on Drug Use and Health (NSDUH) showed that the prevalence of past-year SI among adults ages 18–25 years increased by approximately 47% (8.3% to 12.2%) between 2015 and 2019 (), reaching 12.6% in 2024 (). Despite this burden, only 40.6% of young adults ages 18–25 years with SI reported receiving mental healthcare during this period (). Between 2008 and 2019, the adjusted odds of SA increased 81% among young adults ages 18–25 years, with 35%-46% of adults with an SA reporting an unmet need for mental health services (). In 2023, an estimated 2.2 million adults reported a SA, with the highest prevalence among those ages 18–25 years (2.0%) (). NSSI, which is most prevalent among adolescents and young adults ages 14–24 years (), has been found to be a strong predictor of progression from SI to SA (). Certain subpopulations face elevated risk for STBs. Gender minority (transgender, nonbinary, and gender diverse; TGD) young adults report SI rates as high as 66% (), and sexual minority individuals (lesbian, gay, bisexual, queer, and other non-heterosexual individuals) have significantly greater odds of all forms of suicidal behaviors compared to heterosexual peers (). Prior research has also identified multiple psychosocial and clinical risk factors for STBs among U.S. adults, including unemployment, serious psychological distress (based on a clinically elevated score on the 6-item Kessler Psychological Distress Scale) (), major depressive episodes (), adverse childhood experiences (, ), and comorbid physical and psychiatric health conditions (). In contrast, studies have found that perceived social support is protective against STBs in young adults (, ). Depressive disorders are strongly associated with risk for STBs (). The prevalence of major depressive episodes among adults ages 18–25 years has nearly doubled since the mid-2000s, increasing from 8.8% to 15.9% in 2024 (, ), with estimates as high as 17.2% in 2020 prior to NSDUH methodology changes (). However, increases in depression prevalence have not been matched by improvements in treatment engagement, and a substantial and widening treatment gap persists (). From 2015 to 2019, depression prevalence increased significantly among young adults without commensurate increases in help-seeking (). Approximately half of young adults ages 18–25 with any mental illness received no treatment in 2024, with access disparities further stratified by race/ethnicity and sexual and gender minority status (). This treatment gap is clinically consequential, as a shorter duration of untreated depression is associated with significantly higher odds of treatment response and remission (), potentially mitigating prolonged risk for STBs.