Counselling versus low-intensity cognitive behavioural therapy for persistent sub-threshold and mild depression (CLICD): study protocol for a pilot/feasibility randomised controlled trial

Persistent sub-threshold depressive symptoms are important because almost all patients who experience symptoms for more than 2 years go on to develop major depressive episodes. The National Institute for Health and Care Excellence in the United Kingdom recommends research into the efficacy of person centred counselling and low-intensity cognitive behavioural therapy for persistent sub-threshold and mild depression. A two-arm, parallel group, pilot randomised trial to test the key components of trial delivery. The participants will be 50 patients with the diagnosis of persistent sub-threshold depressive symptoms and mild depression, recruited at five general practices in Glasgow, Scotland. Eligible patients will be randomised to receive either Person-Centred Counselling (PCC) or Low-Intensity Cognitive Behavioural Therapy (LI-CBT). The primary outcome measures are recruitment, adherence and retention rates at six months from baseline. The secondary outcome measures are changes at 6 months on GRID-HAMD-17; recovery from, or prevention of, depression according to DSM-IV diagnosis at 6 months; changes at 6 months on the PHQ-9, WSAS, EQ5D, and SF12v2 MH Enhanced. We will provide estimates, with adequate precision, to help design future studies, of the recruitment rate and the proportion followed-up at 6 months; and identify potential moderators of outcome. Evidence of comparative effectiveness of commonly used psychological treatments such as person-centred counselling and low intensity cognitive behavioural therapy is lacking in patients with sub-threshold and mild depression. This study will provide the information needed to construct a trial comparing these two treatments. This would help to inform early intervention treatment strategies for these conditions.