06 - Effects of caffeine on different disorders

Effects of caffeine on different disorders

904 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 12 Energy drinks So-­called energy drinks contain large amounts of caffeine along with sugar, vitamins and a number of other ingredients such as guarana and taurine. There is some evidence that these drinks can improve attention and short-­term memory.20 Marketing is targeted at adolescents and young adults, some of whom consume large volumes of these drinks and seem to be particularly vulnerable to developing signs and symptoms of caffeine intoxication. Symptoms of anxiety and depression, frank suicidal behaviour and seizures have been associated with use of these products by young people.21–23 When combined with alcohol, aggressive behaviour may result.24 Excessive intake may lead to acute psychosis25,26 or mania.27 Effects of caffeine on different disorders Schizophrenia ■ ■Patients with schizophrenia often consume large amounts of caffeine-­containing drinks1 and they are twice as likely as controls to consume >200mg caffeine/day.6 ■ ■Caffeine-­containing drinks may be used to relieve dry mouth (as an adverse effect of some antipsychotic drugs), for the stimulant effects of caffeine (to relieve dysphoria/ sedation/negative symptoms)6 or simply because coffee/tea drinking structures the day or relieves boredom. ■ ■Schizophrenia may increase sensitivity to drug-­related cues.6 ■ ■Moderate caffeine intake may improve cognitive and negative symptoms in schizophrenia.28,29 ■ ■Large doses of caffeine can worsen psychotic symptoms6,30 (in particular elation and conceptual disorganisation) and result in the prescription of larger doses of antipsychotic drugs. ■ ■The removal of caffeine from the diets of chronically disturbed (challenging behaviour) patients may ultimately lead to decreased levels of hostility, irritability and suspiciousness31 although this may not hold true in less disturbed populations.32 ■ ■Caffeine cessation may be of benefit in clozapine-­resistant schizophrenia.33 Box 12.1  Symptoms of caffeine intoxication ■ ■Restlessness ■ ■Gastrointestinal disturbance ■ ■Nervousness ■ ■Muscle twitching ■ ■Excitement ■ ■Rambling flow of thought and speech ■ ■Insomnia ■ ■Tachycardia or cardiac arrhythmia ■ ■Flushed face ■ ■Periods of inexhaustibility ■ ■Diuresis ■ ■Psychomotor agitation