A permanent tattoo is created by inserting a pigment just below the dermal–epidermal junction of the skin with a needle or a similar implement. The pigment is attacked by the immune system and sits in macrophages and fibroblast cells, producing permanent coloration of the skin. Historical records indicate that the practice of tattooing has been part of human culture since ancient times, with its popularity waxing and waning depending on the existing cultural norms.

The presence of a tattoo has often been considered to signify something about the bearer. As discussed below, previous literature shows some association with psychiatric disorders and criminality. In this article we explore the history of tattooing, motivations for acquiring a tattoo and its relevance to psychiatric practice. In occasional circumstances, psychiatrists may be required to advise a patient wanting a tattoo. It is worth noting that although tattooing is generally associated with body art and decorative body modification, it also has important cosmetic uses after surgery, for example in patients with breast cancer.

Tattoos vary enormously in design, location, number and content. There is no agreed classification of tattoos but one early attempt divides them into seven groups (Reference Ferguson-Rayport, Griffith and StrausFerguson-Rayport 1955):

• identification tattoos (service emblems; personal information; key life events) • love tattoos (idealised, sentimental or maternal love; pornographic images) • bombastic and pseudo-heroic tattoos (Skull and crossbones, ‘Death before Dishonour’, powerful animals) • inveighing fate (horse shoe with ‘Good Luck’; ‘Friday the 13th’) • religious and commemorative • private symbols (of significance only to the individual) • miscellaneous (animals, birds, flowers).

Implications for clinical practice The relevance of tattoos needs to be seen in the context of the prevailing culture. With increasing popularity of the practice and increasing prevalence, a large proportion of individuals with tattoos will be of little significance to a psychiatrist. However, tattoos are overrepresented in marginal groups in society, which often come in contact with the psychiatric profession, whether in the community, in-patient or prison setting, and can provide clinically useful information. Their presence and type can give clues to the existence of particular psychiatric conditions and to the inner world of patients. Tattoos are sometimes acquired for a variety of complex psychological reasons, exploration of which in a therapeutic setting can prove useful. If seen as a form of non-verbal communication, they give clues to important personality traits (such as impulsiveness and risk-taking) that can be relevant to general lifestyle and clinical treatment. We recommend that tattoos are noted during the psychiatric examination and a record is made of their characteristics (location, size and content). The reasons and motivation for acquiring the tattoo(s) should be explored. Another benefit of recording tattoos is that they can be used for person identification. Psychiatrists need to be aware of the medical complications surrounding the procedure of tattooing and be able to give appropriate advice to their patients if they wish to acquire a tattoo. The issue of capacity must be considered in a patient seeking advice on obtaining a tattoo. For example, a patient's wish to obtain a tattoo may be related to their disturbed mental state. In such circumstances, there is a potential risk that a patient will subsequently bring legal action against the doctor, if they were allowed to obtain a tattoo while in an altered mental state. The assessment of capacity is particularly relevant to clinicians working with adolescents, the most common age group for acquiring tattoos. Owing to the high proportion of adults subsequently regretting their tattoos and the associated psychological and social distress, clinicians should be aware of the methods of tattoo removal.