Access to timely care is a quality standard underpinning many international healthcare models, and long waiting times for child and adolescent mental health services are often reported as a barrier to help-seeking.

The aim of this study was to examine whether young people with more severe problems have shorter waiting times for mental health services.

Multilevel multinomial regression analysis controlling for service-area deprivation, age, gender, ethnicity, referral source and contextual factors was conducted on N = 21 419 episodes of care (mean age 12.37 years (s.d. = 3.71), 11 712 (55%) female) using data from child and adolescent mental health services.

There was high variation in waiting times, which ranged from 0 days to 1629 days (mean 50.65 days (s.d. = 78.03), median 32 days). Compared with young people with less severe problems young people with severe problems, self-harm, psychosis or eating disorders were less likely to experience longer waiting times. Moreover, referrals from sources other than primary care were generally less likely to have longer waiting times than referrals from primary care sources, especially referral from accident and emergency services.

The findings suggest that young people with more severe problems had shorter waiting times. Intermediary information and resources for support before access to services is needed to prevent escalation of problems and to support individuals and families while waiting for care. Interventions to reduce waiting times should be considered without compromising on the quality and experience of care that young people and families deserve when seeking help.

Literature has focused on effect sizes rather than individual-level improvement rates to determine how effectively services address burgeoning numbers of adolescents with anxiety and depression.

To consider how many adolescents report reliable improvement in anxiety, depression and comorbid depression and anxiety by end of treatment.

The primary outcome was reliable improvement (i.e. change greater than likely the result of measurement error) in self-reported anxiety and depression for N = 4464 adolescents (mean age 14.5 years, s.d. = 1.9; 75% female; 61% White) seen in specialist mental health services in England.

In total, 53% of those with anxiety, 44% with depression, and 35% with comorbid depression and anxiety showed reliable improvement.

Improvement rates were higher than previously reported, but lower than generally used in advice to the public. There may be a need to set more realistic expectations, including with young people who seek help.

All authors were involved in the programme of service transformation that this report draws on. M.W. led the outcomes and evaluation group that agreed the approach to measurement used in the initiative.