ADRs Affecting the Neuropsychiatric System

Somnolence (ADR #13), sleepiness or drowsiness, may be caused by numerous medications such as antihistamines, antidepressants, anxiolytics, antihypertensives, anticonvulsants, muscle relaxants, and opioids.⁴⁵ The use of alcohol and street drugs, such as marijuana and heroin, can cause drowsiness, as can some herbal teas and supplements, such as valerian.⁴⁶

Insomnia (ADR #9) is a symptom characterized by difficulty falling or staying asleep. It is most often caused by psychiatric disorders, such as, mood disorders and anxiety.⁴⁷ Drug-related insomnia may be associated with chronic drug use or result from drug withdrawal. The use of alcohol, anticonvulsants, antidepressants, and thyroid hormone therapy may interfere with sleep. The withdrawal of CNS depressants such as opioids, benzodiazepines, alcohol, cocaine, and heroin may also lead to insomnia.⁴⁷

Depression (ADR #19) is a mental state dominated by a lowering of mood and often includes other symptoms such as anxiety, agitation, sleep disturbances, alteration in appetite, and feelings of unworthiness, and suicidal thoughts.^14,48 It is a possible consequence of treatment with β1-adrenergic receptor antagonists, digoxin, benzodiazepines, corticosteroids, levodopa, phenothiazines, and steroids.⁴⁸ It should be noted, however, that depression may be an appropriate response to transient life-stress situations.

Anxiety is the distressing experience of dread and foreboding; an unpleasant emotional experience characterized by nervousness, uneasiness, and fear.⁴⁹ Anxiety may be related to medical illnesses, psychiatric illnesses, or psychological illnesses. Symptoms of anxiety may be caused by antipsychotic drugs, anticholinergic agents, digitalis, amphetamines, caffeine, cocaine, as well as withdrawal of alcohol or sedative-hypnotics.⁴⁹