When to prescribe

A thorough assessment of the patient is required before a psychotropic drug can be prescribed. For the more severe mental illnesses, drugs are the most appropriate and effective treatment; for example, schizophrenia should be treated with an antipsychotic drug and severe depressive illness with an antidepressant. However, for the majority of disorders, effective non-drug treatments are also available. For example, depressive illness of moderate severity responds equally well to some forms of psychotherapy as to drugs. In these circumstances the appropriate treatment should be negotiated with the patient, taking into account their wishes and the available resources.

Adherence to medication

Adherence is a measure of the extent to which patients follow the recommendations of the prescriber. The outdated paternalistic view of the relationship between doctor and patient – the former giving instructions, and the latter expected to follow them, is unhelpful. In prescribing any medication we should be aiming for ‘concordance’. This implies a two-way process in which the doctor gives all of the information required to support the patient in reaching a decision that is mutually satisfactory. It is rare in psychiatry to be in a situation in which only one drug option is available. Where there are several options there are likely to be variations in side effects, dosing regimes and mode of delivery for which the patient may have a preference. For example, given the choice of taking an oral antipsychotic drug daily or having a depot antipsychotic injection once a fortnight, some patients with schizophrenia will choose the depot. This may be counter-intuitive from the doctor’s perspective, and so the best decision can only be made by reaching concordance.

Adherence with psychotropic drugs is known to be poor (Fig. 1). Up to half of all patients on prescribed medication for chronic conditions do not take the medication as prescribed. Many patients fail to take the drug at all; others take it at a lower dose or for a shorter period than recommended.

Fig. 1 Reasons for poor compliance.