Depressive disorders are characterised by persistently low mood and loss of interest and pleasure in previously enjoyed activities, as well as a range of other emotional, cognitive, physical and behavioural symptoms, including sleep and appetite disturbance, reduced energy, concentration difficulties, feelings of guilt or worthlessness, and suicidal ideation.1
Clinically significant depression differs from regular mood fluctuation in its severity and persistence. When symptoms appear resistant to change in circumstance, and when they interfere with psychosocial functioning, assistance from a psychologist should be sought.1
Routine screening for depression has been recommended for various at-risk groups, including women in the perinatal period2 and individuals with chronic physical conditions.3
Both self-rating scales and clinician-administered interviews can be useful in the assessment of depression, although the results of these should always be viewed in the context of information obtained in a full clinical interview.4
There is strong evidence to indicate that a number of psychological interventions are effective in achieving and maintaining remission of depression symptoms, including cognitive behavioural therapy and interpersonal psychotherapy.5 Dominant evidence-based models of depression indicate that psychological treatments should include an exploration of the client's thought patterns and strategies to increase behaviours which improve day-to-day functioning.