Everyone experiences periods of time when they feel sadder or more down than usual. This is both normal and expected—decreases in mood are natural responses to certain life experiences (e.g. stress, the death of a loved one, or the end of a significant relationship). But when is a decrease in mood a sign of depression? Depression is not the same as simply feeling sad; someone who is experiencing depression may feel sad, but he or she must also experience a number of other symptoms that considerably impair the quality of his or her life.
What are the symptoms of depression?

Not all depression looks and feels the same. Depression may vary greatly in intensity level, the amount of time you have felt depressed, and the number of noticeable periods you have felt depressed. It is important to note that all types of depression, mild through severe, have the potential to significantly affect your life (e.g. your ability to function at work or the quality of your personal relationships).

The following list includes some of the most common symptoms of depression:

  • Feeling depressed or down most of the time
  • Losing interest or pleasure in things you usually enjoy
  • A large increase or decrease in your appetite or weight
  • Sleeping too much or not being able to sleep enough
  • Feeling either very tired or as if you have lost most of your energy
  • Feeling worthless or having low self-esteem
  • Feeling hopeless
  • Feeling extremely guilty for reasons you may not be able to explain
  • Having difficulty concentrating or making decisions
  • Having recurrent thoughts of death
  • Having recurrent thoughts of wanting to commit suicide
  • Treatment

Cognitive-Behavioural Therapy (CBT) is a scientifically researched type of psychotherapy that looks at how our behaviours, thoughts and feelings strongly affect one another; it has been proven to be the most effective treatment for depression. CBT works to help people evaluate and respond to negative thoughts and behaviours because these unintentionally contribute to and help to maintain depression.
We do not mean to say that depression is easily solved by simply changing how you think; Cognitive-Behavioural Therapy simply gives you a way of better understanding how your  behaviour and negative thoughts affect how you respond to different situations, and in turn, how you feel. Most importantly, CBT gives you the specific tools to change these negative thoughts and behaviours so you will be able to work your way out your depression.