Ask about symptoms suggesting psychological vulnerability, such as irritability, feeling uneasy, constant tiredness, suspiciousness, and withdrawal.

If you suspect psychosis, ask more about changes in social functioning, such as problems in relationships with friends and family; cognition, such as poor concentration or memory; mood, such as feeling depressed, anxious, or irritable; and thought content, such as preoccupation with strange thoughts or ideas that seem hard to ignore (for example, “have you felt lately that people are talking about you, plotting about you, or trying to hurt you?”).

Ask about drug misuse. Although there is no compelling evidence to suggest a causal role for drug misuse in first episode psychosis, drug misuse can cause prolonged and more severe symptoms. However, referral for assessment for psychosis should not be delayed just because, for example, he smokes cannabis.

Look for evidence of poor personal hygiene, delusional or bewildered mood, abstract or vague speech, or outbursts of anger or irritation; these also suggest psychosis.

Psychosis rarely presents in neat parcels, and symptoms are rarely volunteered spontaneously. You may need to see him more than once to gain a full picture.

Ask his permission to talk to his family, for a fuller picture of his behaviour at home. This will also enable you to ask in detail about family history of psychosis (risk of psychosis increases with a family history).

Do not “wait and see” what happens or dismiss symptoms as part of adolescence or depression or as secondary to drug misuse. Studies on first episode psychosis have found an average one to two year delay between onset of symptoms and start of treatment. Current evidence suggests that early monitoring and treatment may be associated with a better treatment response and outcomes.

If symptoms do not require immediate referral, then keep an active watching brief. Symptoms may become clearer once some trust is established. If he fails to attend a subsequent appointment, do not assume that symptoms have settled—make contact with him to check.

If a diagnosis of possible psychosis is likely, you will need to ensure he is being seen by an appropriate service, such as the local psychiatric team, for assessment. (During the next three years, 50 specialist “early intervention” teams will be set up in England and Wales to provide assessment, treatment, and active support in the community for young people with a first episode of psychosis.)

It is important to work with his family as therapeutic allies and be aware of the carers' health needs. In the longer term you may need to help them obtain information and practical assistance and provide emotional support.

Occasionally, family members present with concerns about a son or daughter. If they cannot persuade him or her to come to the surgery and the situation seems sufficiently serious, you should make a home visit. If the family feels their child may behave aggressively, then consider a joint visit with an experienced community psychiatric nurse.