The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent...

Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...

The sleep cycle, an integral part of human health, consists of several stages with distinct characteristics and functions. It begins with a transition from wakefulness to sleep, known as the light sleep phase, followed by the restorative deep sleep phase, essential for physical recovery and growth. The cycle concludes with the Rapid Eye Movement (REM) phase, characterized by high brain activity and vivid dreaming. Insomnia, a prevalent sleep disorder, involves difficulty falling asleep, staying...

Bipolar disorder is a chronic mental health condition marked by significant mood fluctuations, including episodes of mania and depression. Elevated energy levels, heightened mood or irritability, impulsive behavior, reduced sleep needs, rapid speech, racing thoughts, inflated self-esteem, and distractibility characterize mania. Individuals with bipolar disorder often alternate between depressive and manic states, with periods of emotional stability lasting an average of six months to a year.

Chronic stress profoundly affects mental health, significantly influencing mood, behavior, and overall quality of life. Research closely links chronic stress with mental health conditions such as depression, anxiety, and substance use disorders. Ongoing exposure to stress can lead to physiological and psychological changes, initiating a cycle of emotional distress and maladaptive coping mechanisms.
Individuals with depression often experience challenges in both their personal and professional...

Obsessive-compulsive disorder (OCD) is a mental health condition characterized by recurrent obsessions, compulsions, or both, which consume significant time and interfere with daily functioning. Obsessions involve persistent, intrusive, and unwanted thoughts, images, or urges that evoke anxiety. Common examples include irrational fears of contamination or harm. Compulsions are repetitive behaviors or mental acts performed to reduce the anxiety caused by obsessions. For instance, individuals...