Lithium versus Quetiapine in Depression (LQD)

The LQD study is investigating which of two medications (lithium or quetiapine) added to an antidepressant is best in helping people with treatment resistant depression. Both lithium and quetiapine are currently recommended in treatment guidelines for treatment resistant depression. The aim of the study is to address the gap in the research literature on which of these medications is most clinically and cost effective over the course of a year. Future patients will benefit from the results of the study by knowing which (if any) treatment is more likely to improve their condition over a longer duration of time.

The study is being run by South London and Maudsley NHS Foundation Trust (SLaM)across various sites including Newcastle, Oxford, and Brighton. In the North East, we are currently recruiting patients from Cumbria, Northumberland, Tyne and Wear NHS Foundation Trust. Further information can be found here LQD Study.

What does participation in the study involve?

We are looking for 214 people that are currently experiencing depression to join the study. We will use a randomisation process (like tossing a coin) to assign 50% of participants to lithium, and 50% to quetiapine. Participation will be over 12 months, during which time there will be an initial screening and baseline assessment (both of which may be on the same day), and follow up assessments 8, 26 and 52 weeks later. The assessment sessions will involve a series of questionnaires with a trial researcher and optional blood tests.

Participants in the trial may stop taking the medication before the one-year trial duration but we would still like to follow all participants in the study over 52 weeks to determine the long-term effects of the decision to prescribe each medication.

What are the possible benefits of taking part?

The study medications may improve your symptoms of depression. There is the possibility that the study may not directly benefit you but if you do decide to take part, you will be helping medical research. The results of this study could help guide future clinical practice by informing us about which (if any) treatment is most effective.

Can I take part?

To take part in the study, you will need to meet the following eligibility criteria:

  • Over 18 years old
  • Are currently experiencing depression and have taken two or more antidepressants in the current episode
  • No diagnosis of bipolar disorder
  • No current diagnosis of psychosis
  • No lithium or quetiapine treatment in your current episode of depression
  • You must not be participating in another clinical trial
  • You must not be pregnant, breastfeeding, or currently actively trying for pregnancy

View the Participant Information Sheet.

For more information about the study and how to refer a patient, please contact the research team: or