“Psychology Works” Fact Sheet: Depression

What is depression?

Almost everyone feels sad or “depressed” at certain times. Clinical depression (also called Major Depressive Disorder or MDD) is confirmed by the presence of at least five symptoms for at least a two week period.

The possible symptoms of Clinical depression include sadness, loss of interest in usual activities, changes in appetite, changes in sleep, changes in sexual desire, difficulties in concentration, a decrease in activities or social withdrawal, increased self-criticism or reproach, and thoughts of, or actual plans related to suicide.

Clinical depression may vary in its severity and in its extreme forms can be life threatening and may require hospitalization.

Whereas Clinical depression is a more severe form of depression which can be fairly time-limited, Dysthymic Disorder (also called Dysthymia) is a less-severe, but more chronic type of depression.

Dysthymia is recognized when three of the symptoms listed above are present for at least two years. Some individuals also experience what is called “double depression”; this situation occurs when a person has ongoing Dysthymia, but from time to time also meets the criteria for Clinical depression.

Major Depressive Disorder is distinguished from Manic Depression or Bipolar Disorder in that in MDD the individual only experiences periods of depression, and potentially returns to normal functioning in between times. In Bipolar Disorder, however, the individual will cycle between depression and periods of hypomania or full manic problems (euphoria, high energy, lots of activity).

Approximately 1% of Canadian men and 2% of Canadian women are clinically depressed at any point in time and about 5% of men and 10% of women will experience clinical depression at some point in their life. Women are at about twice the risk of men to experience clinical depression. These rates of depression are fairly consistent in various countries around the world.

Depression is often a recurring condition, as a person who has had one episode of clinical depression is at high risk for repeated experiences, and this risk of recurrence increases with each subsequent episode. Prevention, early assessment and intervention are thus recognized as critical aspects of health care.

Although the causes of clinical depression are complex and vary from individual to individual, it is now clear that a variety of factors increase the risk of a person experiencing clinical depression.  Women may face an increased time of risk after childbirth.  Other risk factors include having a parent who has been clinically depressed, physical illness or ongoing disability, the death or separation of parents, major negative life events (in particular, events related to interpersonal loss or failure), pervasive negative thinking, physical or emotional deprivation, and previous episodes of depression.

Some individuals experience depression in a regular seasonal pattern. Finally, some medical conditions and the effects of some medications can either look like, or induce, a depressive episode.

What psychological approaches are used to treat depression?

Given the large number of people who experience depression and its profound negative effects, psychologists have devoted considerable effort to study depression and develop effective treatments. These efforts have resulted in a number of treatments with evidence to support them.

Cognitive therapy is the most well-studied psychological treatment for depression and has the most consistent evidence to support its use.

Cognitive therapy involves the recognition of negative thinking patterns in depression and correcting these patterns though various “cognitive restructuring” exercises. Cognitive therapy also uses behaviour change strategies.

Cognitive therapy has been shown to successfully treat approximately 67% of individuals with clinical depression. Alone among all the treatments for depression, accumulating evidence suggests that cognitive therapy reduces the risk of having a subsequent episode of depression.

Behaviour therapy helps patients increase pleasant activities and overcome avoidance and withdrawal through efforts to become more engaged in the world.

Behaviour therapy also teaches strategies to cope with personal problems and new behaviour patterns and activities. Behaviour therapy is offered in individual or group therapy and works about 65% of the time.

Interpersonal therapy is another treatment for depression, based on the idea that interpersonal stresses and dysfunctional patterns are the major problems experienced in depression.

Interpersonal therapy teaches the individual to become aware of interpersonal patterns and to improve these through a series of interventions. Interpersonal therapy has a success rate that is comparable to behaviour therapy and cognitive therapy.

Short-term psychodynamic therapy is a treatment which focuses on the identification of core conflictual themes in the way a person thinks about themselves or their interpersonal relations, some of which may be unconscious.

This treatment approach uses the therapeutic relationship as a model for other relationships and uses corrective experiences in therapy to lead to other changes in the depressed person’s life. Evidence suggests that the efficacy of Short-term psychodynamic therapy is comparable to other treatments for depression.

In addition to the above treatments, several other psychological treatments have promise in treating depression. These treatments have some evidence to support their use although they are not as well-established as the first three treatments.

Reminiscence therapy is a treatment that has been developed for older adults. It involves teaching people to remember times when the individual was younger and functioned at a higher level than as a depressed older adult.

Self-control therapy and Problem-solving therapy are treatments which combine some elements of cognitive and behaviour therapy for depression and teach better self-control and problem-solving behaviours in problem situations. A regular routine of moderate aerobic exercise has also demonstrated reductions in depression.

An important note about psychological treatments for depression is that they are roughly as successful as pharmacotherapy for depression.  In fact, psychological treatments often have significantly lower drop-out rates than pharmacotherapy (approximately 10% in psychological therapies versus 25-30% in drug therapy) which may be related to the fact that drug therapies for depression often have unpleasant side-effects.

There is some evidence that cognitive therapy in particular reduces the risk of relapse relative to those individuals who are treated with drug therapy. Other treatments for depression include electroconvulsive therapy and light therapy (the latter for people who suffer Winter-time Seasonal Depression, also called Seasonal Affective Disorder; SAD).

Psychological treatments are effective and safe alternatives to drug therapy for depression when provided by a qualified professional psychologist.

Although the evidence is somewhat inconsistent at present, it does not appear that combining drug and psychological treatments significantly enhances the success of either of these treatments alone.

However, because some of the drug therapies may lead to a quick response they may be effectively combined with psychological treatments which provide for longer term change. Further research on the costs and benefits of combined treatments is clearly warranted.

It is also worth noting that psychological treatments that focus on relapse prevention have been developed and tested. One model in particular, called Mindfulness Based Cognitive Therapy, has demonstrated the ability to reduce the risk of relapse, relative to treatment as usual and medications, especially for individuals who experience recurrent depression.

In summary, depression is a disabling and potentially chronic disorder. There are a number of successful treatments, which include psychosocial and biological treatments. Unfortunately, there is no clear way to know in advance to which treatment any one person with depression will respond.

Research does suggest, however, that it is important to identify and treat depression as soon as possible, to prevent its development into a chronic problem. Further, long-term and more severe depression is associated with increased risk of suicide, so timely and effective intervention from a qualified and professional health care provider is recommended.

Where do I go for more information?

You can consult with a registered psychologist to find out if psychological interventions might be of help to you. Provincial, territorial and some municipal associations of psychology often maintain referral services. For the names and coordinates of provincial and territorial associations of psychology, go to https://cpa.ca/public/whatisapsychologist/ptassociations/. The Canadian Register of Health Service Providers in Psychology also has a listing service and can be reached through http://www.crhspp.ca.

This fact sheet was prepared for the Canadian Psychological Association by Dr. Keith Dobson, Department of Psychology, University of Calgary.

Revised: January 2017

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