Depression and anxiety symptom change during psychological therapy for autistic clients: Evidence from national healthcare records in England

Background Autistic people appear less likely to benefit from currently-recommended mental health treatments. Intervention development and adaptation is hampered by a lack of knowledge regarding whether subgroups of autistic people differ in their response to interventions, and what characterises subgroups of autistic people who respond differently. This study aimed to identify trajectories of depression and anxiety symptoms during routine psychological therapy for autistic people in general adult primary care mental health services and describe the characteristics of groups that followed particular symptom trajectories. Methods Sessional anxiety and depression symptom scores for N = 7,175 autistic individuals accessing NHS Talking Therapies, for anxiety and depression (NHS TTad) services between 2012-19 across England were drawn from a linked, national healthcare record dataset (MODIFY). Growth Mixture Models were estimated for depression and anxiety symptom severity change over eight sessions, and latent trajectory classes were described in relation to demographic and pre-treatment clinical variables. Findings Seven different anxiety trajectories, and five depression trajectories were observed. Groups showed stable, improving or deteriorating symptoms during treatment. Trajectories appeared distinct by the third treatment session. Identifying as belonging to an ethnically-minoritised group was associated with increased likelihood of deteriorating anxiety symptom trajectories compared with identifying as of White ethnicity. Lower pre-treatment difficulties in daily living were associated with greater likelihood of following trajectories defined by initially severe depression and anxiety symptoms which then improved during treatment, compared with trajectories that did not improve. Interpretation Findings highlight the value of examining early change in treatment response, and identifying individuals at risk of reduced intervention effectiveness before treatment has begun. After the third treatment session, clinicians could identify a possible change trajectory and consider adapted or augmented intervention if there is no improvement. Interventions should be adapted on the basis of individuals’ cultural backgrounds and neurodevelopmental conditions. Daily living, including social and private leisure (taking account of autism masking and burnout experiences) may be a promising focus for augmented treatment. Funding The funder of the study had no role in the study design, data collection, analysis, interpretation or writing of the report.