The Dark Triad describes the combination of psychopathy, machiavellianism and narcissism.

These traits have often been associated with negative aspects of the personality and share insensitive manipulation, deception and aggression but each has its own distinctive element: psychopathy is related to higher levels of aggression and impulsiveness and is characterized by behaviors aimed at the search for thrills, dishonesty, egocentrism,manipulation and antisocial behavior.

Machiavellianism is linked to hypocrisy, exploitation, insincerity and insensitivity while narcissism is linked to domination, superiority and self-centered attitude, from exhibitionism and the search for admiration.

A lot of researches have focused on the negative consequences these traits can have for society at large. However, relatively little importance has been attached to negative emotional consequences. In fact, in association with this set of traits, high levels of anxiety, alexithymia and problems in emotional regulation have often been traced. The purpose of the study by Gómez-Leal et al (2019) was to explore how the three personality traits that make up the Dark Triad could be related to some depressive symptoms, in particular to continuous depressed mood, low self-esteem, irritability, to changes in appetite and sleep.

Several previous studies have explored the relationship between depression and the three traits separately, but no study has ever considered them together.

The data show that high scores of psychopathy and machiavellianism are related to the presence of depressive symptoms. As for psychopathy, there is currently an open debate on the relationship between this trait and depression, as some authors consider both constructs to be mutually exclusive. This is because psychopathy is intended as an activation disorder, and conversely, mood dysfunctions such as depression which is included among the inhibition disorders.

The authors, however, support the idea that both constructs are not exclusive, and that in fact, proves a positive relationship between them, is precisely the outsourcing of negative moods such as anxiety or depression can cause antisocial and psychopathic behavior.

Compared to machiavellianism, the positive relationship found with depression is inline with previous literature. It is characterized by the emotional detachment that is usually observed in people suffering from depression and anhedonia. As for narcissism, there has been no finding of a positive relationship with depression.

The authors explain this by observing that narcissism is a characteristic which differs from psychopathy and Machiavellianism, in terms of social character because the individual tends to seek positive validation from others. Therefore, people with high scores on this trait often have good social support, which is considered to be a protective factor for mood disorders.

Some of the sub-dimensions of the Dark Triad traits associated with depressive symptoms showed significant differences according to gender. The negative relationship between depressive symptoms and the self-sufficiency dimension of narcissism is stronger in women than men while the relationship with vanity has only been observed in women,while the relationship with contempt for conventional morality has only been observed in men.

The gender differences found in the relationship between vanity and depression could be explained by the fact that, the aspects included in the sub-dimension of vanity are more dominant in women therefore a dissatisfaction with one's body image could justify the depressive symptoms, while self-sufficiency in women is associated with greater economic independence and greater professional success which by guaranteeing a high level of satisfaction with the quality of life, protects them from depressive symptoms.Finally, in men, the highest scores on the dimension of contempt for conventional morality could be linked to a lack of social connections, which could result in higher levels of depression.

From an application point of view, the results of this study could have implications for the implementation of prevention and treatment programs focused on depression in conjunction with Dark Triad. The detection of high scores on certain Dark Triad sub dimensions could be useful preventive interventions, avoiding future depressive symptoms or emotional problems.