Significant numbers of people in England have fallen into a gap between primary care psychological therapies and specialist mental health services. We aim to examine pathways to care by looking at demographic variation in detection and referral to primary and secondary psychological services in south London. Longitudinal descriptive study using a record linkage between a primary care database (Lambeth DataNet) and a secondary care mental health database (CRIS). We extracted data on mental health diagnosis, prescriptions and episodes of care in mental health services for all patients of working age registered from 1 January 2008 to 1 March 2018 (pre-covid era). Of those with a mental disorder detected in primary care (n = 110,419; 26.8%); 33.7% (n = 37,253) received no treatment; 21.3% (n = 23,548) exclusively accessed psychological treatment within NHS Talking Therapies and 7.6% accessed secondary care psychological therapies. People from minoritised groups were more likely to be prescribed psychotropic medication as the only treatment offered compared to the White British group. Men, Black African and Asian groups were less likely to access NHS Talking Therapies. People with a personality disorder diagnosis had the highest prevalence and number of NHS Talking Therapies treatment episodes (48.0%, n = 960), a similar percentage (44.1%, n = 881) received secondary care psychology treatment. Our study highlights marked inequalities in access to psychological therapies for men and people from some minoritised ethnic groups across primary and secondary care and how individuals with personality disorders are offered multiple short-term courses in NHS Talking Therapies even where this is not recommended treatment.