Antidepressants and antipsychotics: anaesthetic implications

According to the World Health Organization about 450 million people suffer from mental and behavioural disorders worldwide, whereas depression has a lifetime prevalence of between 10 and 20%. Antidepressants are broadly divided into four main groups: tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), atypical agents and monoamine oxidase inhibitors (MAOIs). Lithium is also occasionally used as an adjunct to treat refractive depression, but is more commonly used as a mood stabilizer in bipolar affective disorder. Antipsychotics are usually classified as 'conventional' antipsychotics or 'atypical' agents. The anaesthetist has to incorporate these agents in premedication and should anticipate their interactions with anaesthetic technique.