Insomnia is a common sleep complaint that involves difficulty falling asleep and/or staying asleep. It is associated with impaired functioning and significant distress or worry. Other common daytime effects include low mood, irritability, fatigue, poor concentration and memory, and reduced physical well-being. When such sleep difficulties occur at least 3 nights per week, for 3 months or longer, it is considered “persistent”. It is this type of insomnia, in contrast to occasional or more short-lived sleep difficulties, that typically leads a person to seek treatment. About 10% of adults have persistent insomnia, whereas up to 50% report some degree of sleep difficulties.

Occasional anxiety is a normal and adaptive part of the human experience. However, for some people, anxiety is persistent and excessive. People with anxiety disorders have recurring worries about everyday situations. They may also experience a number of physical symptoms, such as a rapid heart rate, trembling, sweating, or feeling keyed up. As a way of coping with their anxiety, they may avoid certain situations or come to rely on safety behaviours (e.g., avoiding eye contact, being overly prepared, seeking reassurance). There are several different types of anxiety disorders such as generalized anxiety, social anxiety, specific phobias, and panic disorder. It is estimated that almost 30% of people will experience an anxiety disorder at some point in their life.

Depression is a mood disorder characterized by persistent feelings of sadness or a loss of interest in activities. Other symptoms may include sleep difficulties, changes in appetite or weight, feeling physically slowed down or agitated, fatigue or low energy, feelings of worthlessness or guilt, cognitive difficulties, and thoughts of death. In order to receive a diagnosis of depression, symptoms must be present more days than not, for 2 weeks or longer. Depression affects approximately 7% of people at any given time, with women being at an increased risk.