psychiatric formulation

Last reviewed 01/2018

The psychiatric formulation consists of:

A summary of the major features.

Differential diagnosis: A list of alternatives in order of their probability. For each diagnosis factors for and against a diagnosis are stated. At the end of the list the most probable diagnosis is stated as a conclusion.

Aetiology of the probable diagnosis Predisposing factors, precipitating factors and maintaining (perpetuating) factors. The reasons for any predisposition are then considered, usually in chronological order to show how each factor built on those that went before.

After aetiology: The conclusions about diagnosis and aetiology are summarised with a list of outstanding problems, and a list of any further investigations required. Positive factors may also be noted.

Treatment: A concise plan of treatment is outlined. This should mention social measures as well as psychological treatments and medication, together with the role of nurses and occupational therapists.

Prognosis: It is wrong to avoid commitment by writing down a vague statement. It is better to make a firm prediction; for example, `These depressive symptoms should recover quickly in hospital but are likely to recur if she stops her medication again.' If the prediction is proved wrong the doctor can learn by comparing it with the actual outcome.