According to statistics published by the World Health Organization (WMO), depression is one of the most common mental disorders. In 2015 WMO estimated that more than 300 million people (the equivalent to 4.4% of the world’s population) were affected by this condition. It was also the most common cause of disability and suicide deaths in the world (approximately 800.000).

Possibly because of its high prevalence, talking about depression has become quite common in everyday life. We will often hear people refer to themselves as depressed when they feel sad, or others who will ensure that a friend or relative is depressed by some situation. And although that could be true in a lot of cases, in order to diagnose depression accurately it is necessary to know exactly what it is, its symptoms, and diagnostic criteria.


According to some authors, Post-Traumatic Stress Disorder (PTSD) is a psychopathological condition that belongs to the category of anxiety disorders, which usually occurs in people that have been exposed to some traumatic experience.

On the other hand, in psychopathological manuals such as the Diagnostic and Statistical Manual of Mental Disorders in its last edition (DSM V), PTSD belongs to the category of Trauma and Stressor Related Disorders, which is pretty much related to anxiety disorders, sharing many of their symptoms and presenting high comorbidity between them. However, in this case, the main feature that allows differentiating PTSD from any anxiety disorder and others psychopathological categories has to do with the fact that the person at some point in his life went through a traumatic episode.

So, in order to understand what PTSD is and is not, there is a term that we must define beforehand: trauma.

We can define trauma as “an unique individual experience of an event or enduring conditions, in which the individuals ability to integrate his/her emotional experience is overwhelmed” , this event often represents for the individual (in a subjectively or objectively way) “a threat to life, bodily integrity, or sanity” (Pearlman and Saakvitne, quoted by Giller, 1999).

Some of the most common traumatic events are usually natural disasters, accidents, wars, rape or in general those that have been a victim of any type of aggression.



Schizophrenia is a chronic mental illness that usually affects young adults. This is why it was previously named as dementia praecox (“precocious madness”) by Dr. Emile Kraepelin. It was later renamed to schizophrenia, as the name was misleading. The word “schizophrenia” comes from the Greek root words schizo (split) and phrene (mind) to describe the fragmented thinking of people with the disorder. This term was not meant to convey the idea of split or multiple personalities – a common misconception. While the term schizophrenia is only about a century old, the disease has been retrospectively found in ancient texts.

Differential diagnosis: Mental illnesses or medical conditions that present similarly to schizophrenia.
Delirium, dementia, substance induced psychosis, bipolar mood disorder, depression, psychotic episode, some personality disorders. Medical conditions like hypothyroidism or hyperthyroidism, pellagra, HIV, syphilis, systemic lupus erythematous and heavy metal toxicity may also present in the same way.