Depressive disorders are characterised by depressed mood and/or loss of interest in previously pleasurable activities. Other features can include feelings of worthlessness, low energy, sleep disturbances and recurrent thoughts of death or suicide. Depression can also occur in the context of bipolar disorder in which an individual alternately experiences periods of euphoria and/or increased energy levels followed by episodes of low mood, anhedonia and loss of motivation.
Depression is associated with a range of functional impairments including an increased risk from suicide and suicide attempts, significant difficulties in performing occupational and social activities, comorbidity with anxiety disorders (such as generalised anxiety disorder, panic disorder and social phobia), physical health problems (such as cardiovascular disease, diabetes, poor immune functioning and some forms of cancer) and increased likelihood of engaging in health-risk behaviours (such as smoking, drug and alcohol abuse, and poor eating habits).
Depressive disorders are highly prevalent in Australia with 12-month prevalence rates estimated at 3.1 per cent for men and 5.1 per cent for women (ABS, 2007). The impact of depression on families and communities is more widespread however, with estimates that 1 in 10 Australians are affected by this disorder (Australian Institute of Health and Welfare, 1999). It has also been estimated that up to 3.7 per cent of children aged between 6 and 17 years suffer from a depressive disorder over a 12-month period (National Survey of Mental Health and Wellbeing, 1998).
General principles of psychological assessment
The diagnosis of depression is formally assessed by an appropriately accredited mental health professional conducting a clinical interview or using a structured clinical assessment tool (such as the Structured Clinical Interview for DSM Disorders [SCID]). This type of interview will include an assessment of current and past symptoms, assessment of functional impairments and behavioural problems, and a case formulation.
Self-report questionnaires (such as the DASS-21, Beck Depression Inventory, K-10) can also be used to assess depressive symptomatology but they are not as reliable as the clinician assessment in assigning a diagnosis of depression. Other methods of assessment include mood monitoring and behavioural observation and reporting through a third party (such as a family member, friend or work colleague).
Evidence-based psychological treatment guidance
Depressive episodes, especially those that are associated with acute stressors, may improve with time in the absence of any treatment. However, if such episodes are prolonged and left untreated, they can result in chronic psychosocial difficulties including poor academic and work performance, damaged social relationships, and low self-worth and self-confidence.
Treatments for depression comprise psychological interventions and pharmacological treatment (for more biologically-driven types of depression). Combined approaches are generally used for more severe, chronic or recurrent depressions (Peterson, 2006).
Established and evidence-based psychological approaches used in the treatment of depression include:
- Cognitive behaviour therapy (CBT) which aims to correct faulty thinking styles
- Pleasant event scheduling to increase exposure to rewarding activities
- Problem-solving skills to overcome feelings of hopelessness and helplessness
- Behavioural therapy/behavioural activation which offsets patterns of inactivity and withdrawal by helping individuals to re-engage in their lives
- Interpersonal psychotherapy (IPT) which focuses on interpersonal problems that may be related to the onset and/or maintenance of a depressive episode.
Emerging treatment directions for the future
Mindfulness-based cognitive therapy (MBCT) has been shown to effectively reduce depression symptoms (Manicavasagar et al., 2011) and prevent relapse (Eisendrath et al., 2008). MBCT helps individuals to become less reactive to their unhealthy negative thoughts and thus ameliorates their depressive mood.
Repetitive transcranial magnetic stimulation (rTMS) is a non-pharmacological medical intervention that is being investigated for the treatment of depression. This procedure involves the application of high-intensity magnetic pulses to the brain which is thought to change neurotransmitter function (Loo & Mitchell, 2005).
Other new treatments include a number of eHealth programs such as ‘myCompass’ and ‘MoodGym’, both based primarily on CBT, which allow individuals to pace their own treatment, track symptoms and monitor their overall progress.
Key reading and information sources
- Depression: The New Integrative Approach (Hammerly, 2001)
- Dealing with depression: A Common sense guide to mood disorders (Parker & Straton, 2004)
- Modelling and managing the depressive disorders: A clinical guide (Parker & Manicavasagar, 2005)
- Black Dog Institute website: www.blackdoginstitute.org.au
- beyondblue website: www.beyondblue.org.au