Psychiatry is the branch of medicine that specializes in the treatment of those mental disorders which primarily cause disturbance of thought, behavior, and emotion. These are often referred to as psychiatric disorders. The boundary with the specialty of neurology, which also deals with disorders of the central nervous system, is therefore indistinct. Neurology mainly focuses on brain disease with clear physical pathology and/or obvious peripheral effects on, for example, motor function.
Mental disorders are complex
Mental disorders such as depressive disorder and psychoses have been recognized since antiquity. Modern epidemiological studies have demonstrated that they are both highly prevalent and widely distributed across all societies.
Overall, mental disorders account for a very high proportion of the disability experienced by the human race. Unfortunately, in most societies mental disorders still do not receive the recognition or a level of health service commensurate with their public health importance.
There are several reasons for this.
- Probably most importantly, the brain is a vastly complex organ and the neural systems underlying mental disorders remain poorly characterized. This inevitably means that our understanding of the pathophysiology is relatively poor compared with disorders such as diabetes or heart disease.
- The absence of a clear body of reliable scientific evidence means that competing unscientific views and stigma can flourish. Recently, however, our neurobiological techniques have improved in sophistication and sensitivity to the extent that mental disorders have become tractable problems.
- Phenomena such as mood symptoms, anxiety, and even psychosis seem to exist on a continuum in the population, and the absence of reliable neurobiological measures creates difficulties in determining where the thresholds lie in the gradual change from normality to illness.
- In clinical practice, the use of diagnostic criteria can increase the reliability of diagnoses and reduce the variations between clinicians. However, small changes in diagnostic criteria can have large effects on the resulting estimates of the prevalence of disorders. Unfortunately, the criteria themselves are based on very imperfect knowledge about the natural history or boundaries of the disorders.
Current treatments for mental disorders can be highly effective
- This combination of limited understanding of pathophysiology, widespread prevalence, and efflorescence of competing unscientific or folk explanations (which a postmodern culture accords equal status) could lead to pessimism about the potential of psychiatry to help people suffering from the reality of mental disorders.
- It is remarkable, therefore, that such effective treatments do exist which, properly implemented, can produce worthwhile clinical benefits. We may not yet have arrived at the stage of rational therapies based on fundamental scientific understanding. Nonetheless, through a combination of speculative creativity and guided serendipity, coupled with rigorous evaluation in clinical trials, we have a range of valuable interventions. Moreover, although again not based on pathophysiological markers reflecting the underlying neurobiology, psychiatry has developed reliable diagnostic systems that create a common language to facilitate communication between clinicians and patients, clinicians and clinicians, and researchers.
- There are compelling reasons for all doctors to have at least a basic awareness of mental disorders and their assessment and effective management. This text aims to provide that basic knowledge. We hope that students will be inspired to follow a career in psychiatry—which can be a rocky road, but one that amply repays the efforts expended by both satisfying intellectual curiosity and providing the unique reward of relieving the suffering of fellow humans.