Final answer:
Stimulants are drugs that stimulate the brain and are used to treat conditions like ADHD. They increase neurotransmitter activity in certain brain areas to improve focus and reduce hyperactivity.
Step-by-step explanation:
Stimulants are drugs that stimulate the brain and increase alertness and wakefulness. They are used to treat conditions such as attention deficit hyperactivity disorder (ADHD). For example, amphetamines are commonly prescribed to individuals with ADHD because they increase neurotransmitter activity in brain areas associated with impulse control, helping to improve focus and reduce hyperactivity. Therefore, the correct answer is (c) anxiety disorders, neuroses, some psychosomatic disorders, and insomnia.