Somnolence, sleepiness or drowsiness, is a symptom characterized by a state of strong desire for sleeping or sleeping for unusually long periods.31 The use of alcohol and street drugs, such as marijuana and heroin, can cause drowsiness.31 Somnolence may also be caused over-the-counter medications such as antihistamines; and prescription drugs such as anxiolytic agents, muscle relaxers, opioids analgesics, and sleeping pills.31 Drowsiness can also be caused by some herbal teas and supplements, such as valerian.31
Insomnia is a symptom characterized by difficulty in falling to sleep or to stay asleep. It is most often caused by psychiatric disorders, i. e., mood disorders and anxiety.31 Drug-related insomnia may be associated with chronic use of drugs or result from drug withdrawal.31 The use of alcohol, anticonvulsants, antidepressants, and thyroid hormones therapy may interfere with sleep. The withdrawal of CNS depressants such as opioids analgesics, benzodiazepines, alcohol, cocaine, and heroin may also lead to insomnia.
Depression is a mental state dominated by a lowering of mood and it often includes other symptoms such as anxiety, agitation, sleep disturbances, alteration in appetite, and feelings of unworthiness, and suicidal thoughts.8,32 It is a frequent consequence of treatment with β1-adrenergic receptor antagonists, digoxin, benzodiazepines, corticosteroids, levodopa, phenothiazines, and steroids.32 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.33 Anxiety may be related to medical illnesses, psychiatric illness, or psychological illness. Dietary causes of anxiety include caffeine and monosodium glutamate (Chinese-restaurant syndrome.33 Symptoms of anxiety may be caused by antipsychotic drugs, anticholinergic agents, digitalis, amphetamines, cocaine; as well as withdrawal of alcohol or sedative-hypnotics.33