Dr Stephen Kellett, BSc, MSc, DClinPsy
BSc Hons – University of Ulster
MSc – Sheffield
Chartered Clinical Psychologist - HCPC registered
Consultant Clinical Psychologist in the NHS since 2000.
Cognitive Analytic Psychotherapist, Trainer and Supervisor – ACAT accredited
Cognitive Behavioural Psychotherapist - BABCP accredited
My research interests fall broadly within the area of outcome across the psychological modalities using a variety of methods from single case experimental designs through to randomized controlled trials. I am also research active in the following areas; cognitive analytic therapy, increasing attendance, stepped care, morbid jealousy, relapse prevention, and hoarding disorder. I am a member of the IAPT Yorkshire and Humber Practice Research Network (IAPT-PRN).
Teaching and administrative duties
I lead the staff teams delivering the PG Cert in Low Intensity Psychological Interventions and the PG Dip in High Intensity Psychological Interventions. These have two intakes each year (March and October). I teach on the DClin Psy at Sheffield and around the country and also train for ACAT. I work in the NHS one day per week (Monday) in a Specialist Psychotherapy Service.
Current Postgraduate Students
- Katy James (PhD - improving outcomes in IAPT services)
- Sophie Pott (PhD - behavioural activation for addictions)
- Mel Simmonds-Buckley (PhD - reducing stasis outcomes in IAPT)
- Ben Lorimor (PhD - relapse prevention in depression)
- MSc students - two per year
- D Clin Psy trainees - two per year
A list of key publications can be found below. For a full list of publications please click here
- Curling L, Kellett S, Totterdell P, Parry G, Hardy G & Berry K (2017) Treatment of obsessive morbid jealousy with cognitive analytic therapy: An adjudicated hermeneutic single-case efficacy design evaluation. Psychology and Psychotherapy: Theory, Research and Practice. View this article in WRRO
- Lucock M, Barkham M, Donohoe G, Kellett S, McMillan D, Mullaney S, Sainty A, Saxon D, Thwaites R & Delgadillo J (2017) The Role of Practice Research Networks (PRN) in the Development and Implementation of Evidence: The Northern Improving Access to Psychological Therapies PRN Case Study. Administration and Policy in Mental Health and Mental Health Services Research. View this article in WRRO
- Sandhu SK, Kellett S & Hardy G (2017) The development of a change model of "exits" during cognitive analytic therapy for the treatment of depression. Clinical Psychology and Psychotherapy. View this article in WRRO
- Meadows J & Kellett S (2017) Development and Evaluation of Cognitive Analytic Guided Self-Help (CAT-SH) for Use in IAPT Services. Behavioural and Cognitive Psychotherapy, 45(3), 266-284. View this article in WRRO
- Berrios R, Totterdell P & Kellett S (2017) Individual differences in mixed emotions moderate the negative consequences of goal conflict on life purpose. Personality and Individual Differences, 110, 18-22. View this article in WRRO
- Kellett S, Simmonds-Buckley M, Bliss P & Waller G (2017) Effectiveness of Group Behavioural Activation for Depression: A Pilot Study.. Behavioural and Cognitive Psychotherapy. View this article in WRRO
- Saxon D, Ashley K, Bishop-Edwards L, Connell J, Harrison P, Ohlsen S, Hardy GE, Kellett S, Mukuria C, Mank T, Bower P, Bradburn M, Brazier J, Elliott R, Gabriel L, King M, Pilling S, Shaw S, Waller G & Barkham M (2017) A pragmatic randomised controlled trial assessing the non-inferiority of counselling for depression versus cognitive-behaviour therapy for patients in primary care meeting a diagnosis of moderate or severe depression (PRaCTICED): Study protocol for a randomised controlled trial.. Trials, 18(1), 93-93. View this article in WRRO
- Berrios R, Totterdell P & Kellett S (2017) When Feeling Mixed Can Be Meaningful: The Relation Between Mixed Emotions and Eudaimonic Well-Being. Journal of Happiness Studies. View this article in WRRO
- Evans M, Kellett S, Heyland S, Hall J & Majid S (2016) Cognitive Analytic Therapy for Bipolar Disorder: A Pilot Randomized Controlled Trial. Clinical Psychology and Psychotherapy. View this article in WRRO
- Hall J, Kellett S, Berrios RE, Bains MK & Scott S (2016) Efficacy of Cognitive Behavioral Therapy for Generalized Anxiety Disorder in Older Adults: Systematic Review, Meta-Analysis and Meta-Regression. The American Journal of Geriatric Psychiatry, 24(11), 1063-1073. View this article in WRRO
- Delgadillo J, Kellett S, Ali S, McMillan D, Barkham M, Saxon D, Donohoe G, Stonebank H, Mullaney S, Eschoe P, Thwaites R & Lucock M (2016) A multi-service practice research network study of large group psychoeducational cognitive behavioural therapy. Behaviour Research and Therapy, 87, 155-161. View this article in WRRO
- Hague B, Hall J & Kellett S (2016) Treatments for compulsive buying: A systematic review of the quality, effectiveness and progression of the outcome evidence.. J Behav Addict, 1-16. View this article in WRRO
- Poerio GL, Kellett S & Totterdell PA (2016) Tracking potentiating states of dissociation: An intensive clinical case study of sleep, daydreaming, mood, and depersonalization/derealization. Frontiers in Psychology. View this article in WRRO
- Pereira JA, Barkham M, Kellett S & Saxon D (2016) The Role of Practitioner Resilience and Mindfulness in Effective Practice: A Practice-Based Feasibility Study.. Adm Policy Ment Health. View this article in WRRO
- Kellett S, Simmonds-Buckley M & Totterdell P (2016) Testing the Effectiveness of Cognitive Analytic Therapy for Hypersexuality Disorder: An Intensive Time-Series Evaluation. Journal of Sex & Marital Therapy. View this article in WRRO
- Burns P, Kellett S & Donohoe G (2016) “Stress Control” as a Large Group Psychoeducational Intervention at Step 2 of IAPT Services: Acceptability of the Approach and Moderators of Effectiveness. Behavioural and Cognitive Psychotherapy, 44(04), 431-443. View this article in WRRO
- Kellett S, Webb K, Wilkinson N, Bliss P, Ayers T & Hardy G (2016) Developing Services for Patients with Depression or Anxiety in the Context of Long-term Physical Health Conditions and Medically Unexplained Symptoms: Evaluation of an IAPT Pathfinder Site. Behavioural and Cognitive Psychotherapy, 1-15. View this article in WRRO
- Berrios R, Kellett S, Fiorani C & Poggioli M (2016) Assessment of identity disturbance: Factor structure and validation of the Personality Structure Questionnaire in an Italian sample.. Psychological Assessment, 28(4), e27-e35. View this article in WRRO
- Holden K, Kellett S, Davies J & Scott S (2016) The experience of working with people that hoard: a Q-sort exploration. Journal of Mental Health, 1-7. View this article in WRRO
- Hague B, Kellett S & Sheeran P (2016) Testing the Generalizability of Impulse Control Problems in Compulsive Buying. Journal of Social and Clinical Psychology, 35(4), 269-288. View this article in WRRO
- Kellett S, Matuozzo H & Kotecha C (2015) Effectiveness of cognitive-behaviour therapy for hoarding disorder in people with mild intellectual disabilities. Research in Developmental Disabilities, 47, 385-392. View this article in WRRO
- Calvert R, Kellett S & Hagan T (2015) Group cognitive analytic therapy for female survivors of childhood sexual abuse. British Journal of Clinical Psychology, 54(4), 391-413. View this article in WRRO
- Berry K, Haddock G, Kellett S, Roberts C, Drake R & Barrowclough C (2015) Feasibility of a ward-based psychological intervention to improve staff and patient relationships in psychiatric rehabilitation settings. British Journal of Clinical Psychology, n/a-n/a. View this article in WRRO
- Berrios R, Totterdell P & Kellett S (2015) Eliciting mixed emotions: a meta-analysis comparing models, types, and measures. Frontiers in Psychology, 6. View this article in WRRO
- Firth N, Barkham M, Kellett S & Saxon D (2015) Therapist effects and moderators of effectiveness and efficiency in psychological wellbeing practitioners: A multilevel modelling analysis. Behaviour Research and Therapy, 69, 54-62. View this article in WRRO
- Lindsay C, Greve B, Cabras I, Ellison N & Kellett S (2015) Assessing the Evidence Base on Health, Employability and the Labour Market - Lessons for Activation in the UK. Social Policy & Administration, 49(2), 143-160.
- Hague B, Scott S & Kellett S (2015) Transdiagnostic CBT Treatment of Co-morbid Anxiety and Depression in an Older Adult: Single Case Experimental Design. Behavioural and Cognitive Psychotherapy, 43(01), 119-124. View this article in WRRO
- Firth N, Barkham M & Kellett S (2015) The clinical effectiveness of stepped care systems for depression in working age adults: A systematic review. Journal of Affective Disorders, 170, 119-130. View this article in WRRO
- Nattrass A, Kellett S, Hardy GE & Ricketts T (2015) The Content, Quality and Impact of Cognitive Behavioural Case Formulation During Treatment of Obsessive Compulsive Disorder.. Behav Cogn Psychother, 43(5), 590-601.
- Berrios R, Totterdell P & Kellett S (2015) Investigating goal conflict as a source of mixed emotions. Cognition and Emotion, 29(4), 755-763. View this article in WRRO
- Green H, Barkham M, Kellett S & Saxon D (2014) Therapist effects and IAPT Psychological Wellbeing Practitioners (PWPs): A multilevel modelling and mixed methods analysis. Behaviour Research and Therapy, 63, 43-54. View this article in WRRO
- Kellett S, Wilbram M, Davis C & Hardy G (2014) Team consultancy using cognitive analytic therapy: a controlled study in assertive outreach.. J Psychiatr Ment Health Nurs, 21(8), 687-697. View this article in WRRO
- Medard E & Kellett S (2014) The role of adult attachment and social support in hoarding disorder.. Behav Cogn Psychother, 42(5), 629-633. View this article in WRRO
- Ryle A, Kellett S, Hepple J & Calvert R (2014) Cognitive analytic therapy at 30. Advances in Psychiatric Treatment, 20(4), 258-268. View this article in WRRO
- Bains MK, Scott S, Kellett S & Saxon D (2014) Group psychoeducative cognitive-behaviour therapy for mixed anxiety and depression with older adults.. Aging Ment Health, 18(8), 1057-1065. View this article in WRRO
- Kellett S & Hardy G (2014) Treatment of paranoid personality disorder with cognitive analytic therapy: a mixed methods single case experimental design.. Clin Psychol Psychother, 21(5), 452-464. View this article in WRRO
- Calvert R & Kellett S (2014) Cognitive analytic therapy: a review of the outcome evidence base for treatment.. Psychol Psychother, 87(3), 253-277. View this article in WRRO
- Cash SK, Hardy GE, Kellett S & Parry G (2014) Alliance ruptures and resolution during cognitive behaviour therapy with patients with borderline personality disorder.. Psychother Res, 24(2), 132-145.
- Kellett S, Purdie F, Bickerstaffe D, Hopper S & Scott S (2013) Predicting return to work from health related welfare following low intensity cognitive behaviour therapy.. Behav Res Ther, 51(3), 134-141. View this article in WRRO
- Kellett S & Totterdell P (2013) Taming the green-eyed monster: temporal responsivity to cognitive behavioural and cognitive analytic therapy for morbid jealousy.. Psychol Psychother, 86(1), 52-69.
- Kellett S, Bennett D, Ryle T & Thake A (2013) Cognitive analytic therapy for borderline personality disorder: therapist competence and therapeutic effectiveness in routine practice.. Clin Psychol Psychother, 20(3), 216-225.
- Oldham M, Kellett S, Miles E & Sheeran P (2012) Interventions to Increase Attendance at Psychotherapy: A Meta-Analysis of Randomized Controlled Trials. JOURNAL OF CONSULTING AND CLINICAL PSYCHOLOGY, 80(5), 928-939. View this article in WRRO
- Kellett S, Boyden P & Green H (2012) Morbid jealousy: A brief clinical guide to assessment in adult mental health. Clinical Psychology Forum(235), 39-44.
- Thornhill K, Kellett S & Davies J (2012) Heterogeneity within compulsive buyers: a Q-sort study.. Psychol Psychother, 85(2), 229-241.
- Totterdell P, Kellett S & Mansell W (2012) Cognitive behavioural therapy for cyclothymia: cognitive regulatory control as a mediator of mood change.. Behav Cogn Psychother, 40(4), 412-424.
- Robinson S, Kellett S, King I & Keating V (2012) Role transition from mental health nurse to IAPT high intensity psychological therapist. Behavioural and Cognitive Psychotherapy, 40(3), 351-366.
- Purdie F, Kellett S & Bickerstaffe D (2012) Predictors of Functional Disability in Disability Welfare Claimants. Journal of Occupational Rehabilitation, 1-9.
- Kellett S, Bickerstaffe D, Purdie F, Dyke A, Filer S, Lomax V & Tomlinson H (2011) The clinical and occupational effectiveness of condition management for Incapacity Benefit recipients.. Br J Clin Psychol, 50(2), 164-177.
- Manning P, Hardy G & Kellett S (2010) Reversals of sudden gains made during cognitive therapy with depressed adults: a preliminary investigation.. Behav Cogn Psychother, 38(4), 491-495.
- Kellett S, Greenhalgh R, Beail N & Ridgway N (2010) Compulsive hoarding: an interpretative phenomenological analysis.. Behav Cogn Psychother, 38(2), 141-155.
- Davis C, Kellett S & Beail N (2009) Utility of the rosenberg self-esteem scale. American Journal on Intellectual and Developmental Disabilities, 114(3), 172-178.
- Kellett S & Bolton JV (2009) Compulsive buying: a cognitive-behavioural model.. Clin Psychol Psychother, 16(2), 83-99.
- Marriott M & Kellett S (2009) Evaluating a cognitive analytic therapy service; practice-based outcomes and comparisons with person-centred and cognitive-behavioural therapies.. Psychol Psychother, 82(Pt 1), 57-72.
- Beail N, Davies C & Kellett S (2008) The use of the Rosenberg self-esteem scale. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, 52, 728-728.
- Totterdell P & Kellett S (2008) Restructuring mood in cyclothymia using cognitive behavior therapy: an intensive time-sampling study.. J Clin Psychol, 64(4), 501-518.
- Wilbram M, Kellett S & Beail N (2008) Compulsive hoarding: a qualitative investigation of partner and carer perspectives.. Br J Clin Psychol, 47(Pt 1), 59-73.
- Kellett S, Clarke S & McGill P (2008) Outcomes from psychological assessment regarding recommendations for cosmetic surgery.. J Plast Reconstr Aesthet Surg, 61(5), 512-517.
- Kellett S & Matthews L (2008) Reflecting on the clinical, organisational and methodological implications of the Doncaster IAPT site: A commentary onRichards and Suckling. Clinical Psychology Forum(181), 28-30.
- Sheeran P, Aubrey R & Kellett S (2007) Increasing attendance for psychotherapy: implementation intentions and the self-regulation of attendance-related negative affect.. J Consult Clin Psychol, 75(6), 853-863.
- Kellett S (2007) Compulsive hoarding: A site-security model and associated psychological treatment strategies. Clinical Psychology and Psychotherapy, 14(6), 413-427.
- Kellett S (2007) A time series evaluation of the treatment of histrionic personality disorder with cognitive analytic therapy.. Psychol Psychother, 80(Pt 3), 389-405.
- Beail N, Kellett S, Newman DW & Warden S (2007) The dose-effect relationship in psychodynamic psychotherapy with people with intellectual disabilities. Journal of Applied Research in Intellectual Disabilities, 20(5), 448-454.
- Kellett S, Clarke S & Matthews L (2007) Delivering group psychoeducational CBT in Primary Care: comparing outcomes with individual CBT and individual psychodynamic-interpersonal psychotherapy.. Br J Clin Psychol, 46(Pt 2), 211-222.
- Kellett S, Clarke S & Matthews L (2007) Session impact and outcome in group psychoeducative cognitive behavioural therapy. BEHAVIOURAL AND COGNITIVE PSYCHOTHERAPY, 35(3), 335-342.
- Kellett S (2006) The treatment of compulsive hoarding with object-affect fusion informed CBT: Initial experimental case evidence. BEHAVIOURAL AND COGNITIVE PSYCHOTHERAPY, 34(4), 481-485.
- Buckley JV, Newman DW, Kellett S & Beail N (2006) A naturalistic comparison of the effectiveness of trainee and qualified clinical psychologists. PSYCHOLOGY AND PSYCHOTHERAPY-THEORY RESEARCH AND PRACTICE, 79, 137-144.
- Kellett SC & Gawkrodger DJ (2005) A prospective study of the responsiveness of depression and suicidal ideation in acne patients to different phases of isotretinoin therapy. EUR J DERMATOL, 15(6), 484-488.
- Kellett S, Beail N & Newman DW (2005) Measuring interpersonal problems in people with mental retardation.. Am J Ment Retard, 110(2), 136-144.
- Kellett S (2005) The treatment of dissociative identity disorder with cognitive analytic therapy: experimental evidence of sudden gains.. J Trauma Dissociation, 6(3), 55-81.
- Kellett S, Clarke S & Matthews L (2005) Continuous quality improvement using a practice improvement model. Clinical Governance, 10(3), 206-211.
- Kellett S, Beail N, Newman DW & Hawes A (2004) The factor structure of the brief symptom inventory: Intellectual disability evidence. Clinical Psychology and Psychotherapy, 11(4), 275-281.
- Beail N, Newman DW & Kellett S (2004) Routine monitoring: Developing practice based evidence for psychotherapy. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, 48, 300-300.
- Beail N, Kellett S & Newman DW (2004) Measuring interpersonal problems. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, 48, 302-302.
- Beail N & Kellett S (2004) Dose-effect relations in psychotherapy with people with intellectual disabilities (ID). JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, 48, 300-300.
- Kellett S, Newman D, Matthews L & Swift A (2004) Increasing the effectiveness of large group format CBT via the application of practice-based evidence. BEHAVIOURAL AND COGNITIVE PSYCHOTHERAPY, 32(2), 231-234.
- Kellett S & Knight K (2003) DOES THE CONCEPT OF OBJECT-AFFECT FUSION REFINE COGNITIVE-BEHAVIOURAL THEORIES OF HOARDING?. BEHAVIOURAL AND COGNITIVE PSYCHOTHERAPY, 31(4), 457-461.
- Kellett S & Greenhalgh R (2003) A PROCESS MODEL FOR FACILITATING AND ANALYSING CHANGE IN COGNITIVE THERAPY: THE COGNITIVE CIRCUMPLEX. BEHAVIOURAL AND COGNITIVE PSYCHOTHERAPY, 31(3), 347-362.
- Kellett S, Beail N, Newman DW & Frankish P (2003) Utility of the Brief Symptom Inventory in the Assessment of Psychological Distress. Journal of Applied Research in Intellectual Disabilities, 16(2), 127-134.
- Newman DW, Kellett S & Beail N (2003) From research and development to practice-based evidence: clinical governance initiatives in a service for adults with mild intellectual disability and mental health needs.. J Intellect Disabil Res, 47(Pt 1), 68-74.
- Kellett S & Gilbert P (2001) Acne: a biopsychosocial and evolutionary perspective with a focus on shame.. Br J Health Psychol, 6(Pt 1), 1-24.
- Kellett S, Newman DW & Hawes A (2001) The elusive final stages of the audit cycle: Do we put results into action?. Journal of Clinical Governance, 9(4), 187-191.
- Kellett SC & Gawkrodger DJ (1999) The psychological and emotional impact of acne and the effect of treatment with isotretinoin. BRIT J DERMATOL, 140(2), 273-282.
- Kellett SC, Beail N, Newman DW & Mosley E (1999) Indexing Psychological Distress in People with an Intellectual Disability: Use of the Symptom Checklist-90-R. Journal of Applied Research in Intellectual Disabilities, 12(4), 323-334.
- Totterdell P, Kellett S, Teuchmann K & Briner RB (1998) Evidence of mood linkage in work groups. J PERS SOC PSYCHOL, 74(6), 1504-1515.
- Kellett S & Beail N (1997) The treatment of chronic post-traumatic nightmares using psychodynamic-interpersonal psychotherapy: a single-case study.. Br J Med Psychol, 70 ( Pt 1), 35-49.