Professional background

Dr Tyagi is a consultant neuropsychiatrist at the National Hospital for Neurology and Neurosurgery (NHNN), Queen Square. He also holds a specialist qualification in cognitive behavioural therapy (CBT), and is on the General Medical Council (GMC) specialist register for medical pysychotherapy. At the NHNN he works across two departments; as an outpatient consultant in neuropsychiatry and as an inpatient consultant in neurorehabilitation.


Dr Tyagi is part of the team running the National Tourette Syndrome service for adults. This service is based at NHNN and is divided into two streams; a Tourette syndrome general stream and a more specialist stream for patients with a dual diagnosis of Tourette syndrome and obsessive compulsive disorder (OCD).

Dr Tyagi is responsible for the latter stream with a weekly outpatient clinic for Tourette & OCD at Basil Samuel outpatient department on the Queen Square site. This service accepts direct referrals from GP and specialists from anywhere in the country. It also has a limited provision for providing habit reversal therapy and cognitive behaviour therapy for tics for local patients and can manage Tourette patients with neurologically complex presentations within NHNN in close collaboration with other neurologists and neurosurgeons.

Neurorehabilitation and therapy 

Dr Tyagi is an inpatient consultant in neurorehabilitation, providing specialist neuropsychiatric input to patients admitted in a NHS England funded level 1 tertiary neurorehabilitation unit (NRU), also based at Queen Square. In this role, he runs a popular special interest group for psychiatry specialist registrars interested in specialising in neuropsychiatry and offers half day honorary placements at Queen Square. Similar placements are offered to MSc students from courses affiliated with UCLH.

Dr Tyagi’s research interests mainly lie in the field of obsessive compulsive disorder, its related disorders and comorbidities (e.g. Tourette syndrome, body dysmorphic disorder). Prior to joining UCLH at Queen Square in 2016, he coordinated the MRC-UCL randomised controlled trial of deep brain stimulation for severe treatment refractory obsessive compulsive disorder from 2012-2016 in the department of clinical and motor neurosciences at UCL Institute of Neurology.

He completed his basic specialist training in psychiatry at St. Mary’s Hospital, north London and advanced psychiatric training at the National Service for Obsessive Compulsive Disorder (OCD) & Body Dysmorphic Disorder (BDD) at Springfield University Hospital in south London (2009-2012). His training output during advanced specialist training at the OCD unit/psychotherapy was recognised by the Royal College of Psychiatrists with a national award in 2012.

He is also a co-founder and current vice chair of the Royal College of Psychiatrists faculty network for obsessive-compulsive and related disorders (OCARD).

Research interests

Obsessive-compulsive disorder, Tourette syndrome, neurorehabilitation


Selected Publications:

Tyagi, Himanshu, Annemieke M. Apergis-Schoute, Harith Akram, Tom Foltynie, Patricia Limousin, Lynne M. Drummond, Naomi A. Fineberg, et al. 2019. “A Randomized Trial Directly Comparing Ventral Capsule and Anteromedial Subthalamic Nucleus Stimulation in Obsessive-Compulsive Disorder: Clinical and Imaging Evidence for Dissociable Effects.” Biological Psychiatry 85 (9): 726–34.

Tyagi, Himanshu, Lynne Drummond, and Naomi Fineberg. 2010. “Treatment for Obsessive Compulsive Disorder.” Current Psychiatry Reviews 6 (1): 46–55.

Tyagi, Himanshu, Rupal Patel, Fabienne Rughooputh, Hannah Abrahams, Andrew J. Watson, and Lynne Drummond. 2015. “Comparative Prevalence of Eating Disorders in Obsessive-Compulsive Disorder and Other Anxiety Disorders.” Psychiatry Journal.

Akram, H., T. Foltynie, M. Hariz, L. Drummond, E. Joyce, H. Tyagi, M. Marjan Jahanshahi, et al. 2019. “A Direct Comparison of Ventral Capsule and Anteromedial Subthalamic Nucleus Stimulation in Obsessive Compulsive Disorder: Clinical and Imaging Evidence for Dissociable Effects.” Brain Stimulation.

Pampaloni, I., M. Khan, H. Tyagi, and L. M. Drummond. 2017. “Aripiprazole Augmentation in Profound, Sri-Refractory Obsessive-Compulsive Disorder.” European Neuropsychopharmacology: The Journal of the European College of Neuropsychopharmacology 27 (6): 616.