The diagnosis of mental illness

Diagnosis is the stage through which a clinician examines signs (e.g. crying) and symptoms (e.g. feelings of sadness) of a person in order to find out whether they characterize a disabling, endangering disorder. It is an essential process in the field of mental health as it plays a fundamental role in the decision of what treatment to go for. In a perfect world taking into account the interplay between psychological, social and biological factors as well as the influence they exert on the individual would In ancient Greece, as you might have guessed. Well, the term diagnosis itself comes from the Greek diagignoskein which means: to recognize, to distinguish. So, around 400 BC Hippocrates proposed the Humoral Theory that explained and diagnosed mental disorders according to the imbalance existent among the four types of humours that every person possesses. These were meant to be the substances that filled the cavities of the human body and when out of balance would give rise to phobias, melancholy or hysteria; illnesses which were already described and diagnosed back then. This diagnostic system was respected by Muslim, Roman as well as European doctors up to mid-18th century.

be paramount in determining mental illnesses.

That was a time when the emergence of the microscope contributed to a more biological frame of reference. Here the humoral theory gave way to the scrutiny and dissection of organs and tissues. The study of illnesses then was done through a new lens that focused on the biochemical and biological workings of body parts and invisible germs. The biomedical model was born, changing the way mental health was viewed in Western Countries, initiating a mission to differentiate what is ‘normal’ and ‘ill’ while also deciding where to draw the line between both states.

It was within this new climate in the medical field that German psychiatrist Emil Kraepeling put forward the idea that physical and mental disorders should be classified in the same way. In other words, arrange them in groups and subgroups. He then, for the first time, proceeded with differentiating between schizophrenia and bipolar disorder. Kraepelin’s classification system is regarded as a scientific legacy because it made possible for clinicians to foresee the course and outcome of certain mental illnesses. For example, as when he suggested that bipolar disorder (then, known as manic-depressive psychosis) was a disturbance of the individual’s mood resulted from metabolic imperfections.

The diagnosis of mental illness

There are currently two classification systems for mental illnesses: the ICD, published by the World Health Organization and the DSM, published by the American Psychiatric Association. It is worth highlighting here that while the ICD includes other kinds of health problems the DSM addresses solely mental disorders. Despite a few discrepancies both the APA and WHO work together to use the same codes and strive for consistency in order to make the diagnosis process of mental illnesses objective, systematic and exhaustive.

Worldwide, out of the two, the ICD is the preferred one for clinical diagnosis. But, in the USA and the UK the DSM is the classification system most adopted by mental health professionals. The DSM was first published by the APA in 1950. It is currently in its fifth edition and its revisions are based on analyses of data, field trials and reviews of pieces of research.

As new revisions take place an increasing trend in diagnostic categories is seen. For example, the DSM’s first edition included 106 categories while its current edition includes 297. This is because of new acquired understanding of disorders and the influence of social norms. The category corresponding to autism was only included in the 1980’s revision. Naturally, there are also those categories which are eliminated due to the lack of evidence to support them. ‘Substance abuse’ is one of them, as clinicians faced problems in efficiently differentiating it from ‘substance dependence’.

The diagnosis of mental illness