SIR MARTIN ROTH was one of the most respected and successful psychiatrists of his generation. His contributions ranged widely, from the systematic classification and diagnosis of psychiatric disorders, through the delineation, aetiology and treatment of depressive disorders, anxiety and schizophrenia, to the psychiatry of old age — a subject, it has been said, he more or less invented.

He was deeply committed to clinical practice and to rigorous scientific research into the complex interaction of factors causing mental disorders, and their implications for treatment. He also made a significant contribution to consolidating the status of psychiatry and psychiatric training within mainstream medicine.

Besides co-writing the classic textbook of medical psychiatry, Mayer-Gross, Slater and Roth, he was an active force in the establishment of the Royal College of Psychiatrists, its first president, and the first Professor of Psychiatry at the University of Cambridge.

Roth was born into an orthodox Jewish family in Hungary in 1917. After the First World War his father, the cantor in a Budapest synagogue, accepted the post of cantor in a synagogue in the East End of London.

The family arrived in Britain when Roth was about 8. He soon learnt English and devoured the classics, including the works of Shakespeare. After going to the Davenant Foundation — one of two schools in the East End famous for educating a remarkable number of clever Jewish boys — he decided to become a doctor and was awarded a place at St Mary’s Medical School, London. Unfortunately he developed an abdominal complaint which required surgery, and he did not begin his studies until January 1937.

Money was tight, and Roth completed the course as expeditiously as possible. He qualified as MBBS (Lond) in 1942 and, having decided to specialise, picked up higher qualifications with astonishing rapidity: by 1945 he had added MD (Lond) and MRCP (Lond) to his name.

His interest in the mental disorders of old age began in the late 1940s, as he was about to take up the post at the Crichton Royal Infirmary, Dumfries, and he set out some of his early ideas on the biological ageing of the brain in a paper published in 1948. In 1949 Roth was invited to join Willi Mayer-Gross, the director of the institute, and Eliot Slater in writing a new comprehensive Textbook of Psychiatry. The first edition appeared in 1954 and was widely acclaimed. For many years it was the standard work and was translated into five languages.

On moving to the post of director of clinical research at the Graylingwell Hospital, Sussex, in 1950, he and his colleagues began empirical work towards a classification of the psychiatric disorders of old age. This culminated in 1955 in a paper which was the first attempt to differentiate the key features of psychiatric illnesses of the elderly. Important work during this period also included the application of EEG in clinical practice.

In 1956 he was appointed to the chair of psychological medicine in Newcastle upon Tyne where he built up an outstanding centre of clinical psychiatric research, and, with members of his team, carried out crucial research in several fields including depression, anxiety disorders, depersonalisation and old-age psychiatry.

In the latter field, he was responsible for rehabilitating Alzheimer’s forgotten description of Alzheimer’s disease, and for differentiating this from cerebrovascular dementia. He also forged ahead with work on the measurement of declining cognitive function in dementia, and on charting the accompanying neuro-degenerative brain changes first highlighted by Alzheimer in 1907.

Once he was established as Professor of Psychiatry in the medical school at Cambridge, his work on the neuroscience of dementia gathered momentum. He convinced Sir Aaron Klug, the director of the laboratory of molecular biology, of the need to apply the methods of molecular science to studying pathological structures, notably so-called “neuro-fibrillary tangles” observed in abundance in brain tissue from patients with Alzheimer’s disease.

Twenty years’ work by a team, including Claude Wischik, now professor of geratology at the University of Aberdeen, has not only elucidated the characteristic structure, molecular make-up and progressive development of the critical tangle components, but also produced potential treatments, now in clinical trial, aimed at their eradication.

Having fully qualified, Roth decided that neurology was to be his life’s work. Russell Brain, who was on the staff of the Maida Vale Hospital, offered him a job as his registrar. Brain was to have a profound influence on him: Roth was particularly impressed by the importance he attached to the psychological factors in the aetiology of disease. So great was Brian’s influence that Roth decided to change tack and concentrate on psychiatry rather than neurology.

He joined the the Maudsley Hospital, London, at that time the mecca for training in psychiatry in the UK, and was appointed senior registrar to Sir Aubrey Lewis, its pre-eminent psychiatrist. Though Roth derived enormous benefit from his time at the Maudsley, it was not all plain sailing. Lewis had incredible erudition and a waspish tongue. In Roth he had met his intellectual equal, and there were occasional clashes. It may have been these that determined Roth to move on. In 1971 he was elected the first president of the Royal College of Psychiatrists. It was a tough assignment: the main hurdle was the complex protocol of converting a humble association, the Royal Medico Psychological Association, into a Royal College. Equally difficult was finding the cash to buy a splendid late-Georgian town house, 17 Belgrave Square, SW1, but with the persuasive wiles of Roth, the influence of Lord Goodman, among others, and a very substantial gift from the charity trusts of Marks & Spencer, it was done.

Roth was knighted in 1972 and appointed (first) Professor of Psychiatry at the University of Cambridge in 1977. He was elected a Fellow of Trinity College and after his retirement in 1984 he was created Professor Emeritus at Cambridge.

Roth wrote more than 300 papers and received numerous awards, including election as a Fellow of the Royal Society in 1996 — an honour enjoyed by only a handful of psychiatrists.

He was also a wit and a poet manqué. While a student he rowed for the college and took an active part in the music society, even considering the possibility of becoming a professional pianist. He continued to play for his own enjoyment and that of his family and friends. He also had an enormous love and knowledge of European literature and the visual arts.

He is survived by Constance, his wife of 60 years, and by his three daughters.

Professor Sir Martin Roth, FRS, psychiatrist, was born on November 6, 1917. He died on September 26, 2006, aged 88.