The number of murders, suicides and acts of physical violence that are committed by people who are released into the community, after being assessed as no longer a danger to themselves or others, often makes the news.

These cases underline the difficulty of reaching a correct judgment about someone’s psychiatric condition especially when a person is clever, cunning or sophisticated and intent on hiding their troubled feelings and intentions.

Patients with psychotic disease are more likely to be self-effacing than aggressive. Unfortunately anything that emphasises the danger presented by a relapse makes psychiatric medicine even more difficult to pursue.

When my father finally qualified as a doctor after a somewhat chequered academic career, first as a potential parson and later as a medical student and successful cricketer at Cambridge, he worked at a large mental hospital in Surrey, chosen so that he could continue to play cricket.

He was soon in command of the hospital’s cricket side and was delighted that a seemingly well-controlled schizophrenic patient was a good fast bowler. He appointed him cricket secretary and they selected the side together.

As they had become good friends he became lax about standard care. After one pre-match conference my father turned as he reached the patient’s door to wave goodbye. Without warning, he received a potentially lethal blow to his shoulder, so damaging that he couldn’t play cricket for weeks. If he hadn’t turned to give a wave he would have undoubtedly suffered a crippling head injury.

It transpired that for weeks the bowler, as he came up to the wicket or fielded, secreted away one or two of the sharpest and largest stones he could find. Within a month or two the stones, when stacked into a long sock, had been turned into a lethal weapon. The patient never had a cross word with my father, whether over diagnosis, care or the cricket team. Despite long weekly chats the patient had never betrayed any paranoid preoccupations and they had talked just like any other two young university-educated cricketers about non-controversial mutual interests. Most doctors have similar stories. No one can ever be certain what an uncontrolled, disordered mind may do next.

Several weeks before the recent publicity, Marjorie Wallace and Sane, the organisation that she heads and which has made such a difference to the treatment of psychotic diseases, launched a campaign by publishing a booklet Getting Well, Staying Well.

The campaign’s slogan Think Twice has the objective of encouraging people with schizophrenia and bipolar disorder, as well as those who care for them (whether as family members or local health teams) to remember that seven people out of ten experience at least one significant relapse during the course of their illness.

Dr Richard Hodgson, a consultant in adult psychiatry in Staffordshire and an adviser to Sane, says that experiencing a relapse is not only distressing to the individual concerned but also to those around them. Once the relapse has occurred it makes it much more difficult than it was after the first attack to settle happily back into family life, to integrate with their communities and to re-establish their jobs, return to hobbies or resume a social life.

Sane’s booklet discusses the factors that trigger relapses — they rarely come out of the blue. The two most common causes are stress in the patient’s life, or stopping medication. The additional stress that the patient with schizophrenia or bipolar disorder is suffering may be, and usually is, quite unrelated to the person or people who bear the brunt of the ill-effects of the serious relapse. The cricketer who felt murderous towards my father may well have had anxieties about his home life, paranoid delusions or anger about his incarceration. He just happened to project them on to my father because he was the doctor he knew best.

Major life events — including bereavement, divorce, love, birth, moving home, alcohol, or increasingly other drugs, tiredness, ill health or even the time of the year — are important influences on stress and the risk of relapse.

After stress, the most common reason for relapse is that people either stop taking their medication or it has been unwisely changed and the side-effects have proved unacceptable. Conversely and paradoxically the patient may feel so well that they are certain that they no longer need treatment.

Sane’s booklets also suggest how others can spot the first sign of a relapse. The return of an obsession or delusion, new unreasonable anxieties, changes in sleeping pattern or in mood are also possible pointers to trouble ahead. So too are changes in behaviour, including a desire to withdraw from other people.

www.sane.org.uk 0845 7678000