Two Key Studies of Classification Systems (SL IB Psychology)

Aim: To investigate the diagnostic criteria of the DSM-5 with regard to possible culture bias linked to the diagnosis of depression. 

Participants:  16,130 records were used to form the basis of this research which comprised of 138 studies with data derived from 170 samples across 77 nationalities/ethnicities (the total number of participants across the sample is not stated in the original article).

Procedure:  

• A review of qualitative research on depression across the world conducted between August and December 2012 (updated in June 2015)
• Statistics were used to compare features of depression across nationality, region, gender and context i.e. qualitative data was translated into quantitative data
• Four independent experts rated the items from 1-5 on measures such as their credibility, lack of bias and transferability and these ratings were compared with the DSM-5 and other established systems for measuring depression

Results: 

• The DSM-5’s classification for diagnosis of depression agreed with 7 of the 15 features identified by the experts
• Several other features of depression which occur frequently (e.g. poor concentration) were not given priority by the DSM-5 and thus were not included as a standard way of measuring depression
• The DSM-5 model was found to not adequately reflect the experience of depression at worldwide or regional levels i.e. it is overly individualistic and westernised in its approach

Conclusion: The DSM-5 may not be applicable to a range of cultures across the world and may suffer from cultural bias which means that it may lack validity.

Evaluation of Haroz et al. (2017)

Strengths

• The results of the study could be used to inform clinicians to be wary of assuming a universalist approach and to consider the role of culture carefully when forming a diagnosis
• The large sample size should ensure that the quantitative results are robust which should increase the reliability of the findings

Weaknesses

• Using secondary data means that the researchers could not be 100% confident that all the studies included in the research had been conducted with care and attention to detail which would affect the credibility of the research
• Translating qualitative data into quantitative data necessarily involves sacrificing meaning, subjectivity and context so that the data’s explanatory power is lost

A review article uses the findings of previously published research.

Aim: To question whether bereavement-related depression should be excluded from the DSM-5.

Participants:  A community-based sample of participants (who were taking part in the National Epidemiologic Survey on Alcohol and Related Conditions) from the USA who were tested  in two phases (43,093 in phase 1; 34,653 in phase 2). 

Procedure: 

• The participants were part of a retrospective longitudinal study into grieving and depression conducted from 2001 to 2002 and from 2004 to 2005
• The researchers used structured interviews,using the Alcohol Use Disorder and Associated Disabilities Interview Schedule–DSM-IV (DSM-4) version to guide the type of questions asked
• The interview schedule described above was designed to as a diagnostic tool used to diagnose mood, anxiety, substance abuse, and other related disorders
• The researchers measured demographic characteristics of the participants including their age at the onset of their depression; if there was a  history of depression in their family; if they had used mental health services, and any new depressive episodes they experienced during the 3-year follow up period
• Major depressive episodes were defined as having a duration of at least 2 weeks, during which the participant would have experienced 5 or more of the nine DSM-IV (DSM-4)  symptoms, particularly impairment and/or distress

• The qualitative data collected via interview was translated into quantitative data via a specific scoring system

Results: 

• Participants with bereavement-related, single, brief depressive episodes tended to be older at onset, were more likely to be African-American, and were less likely to have had impairment, anxiety disorders or a previous psychiatric treatment history
• These participants were also less likely than other participants with bereavement-unrelated, single, brief depressive episodes to experience fatigue, increased sleep, feelings of worthlessness, and suicidal thoughts
• These participants also had a much lower risk of developing depression during the follow-up period

Conclusion: The DSM-5 should exclude bereavement-related depression from the list of depressive episodes requiring treatment as these can be explained by the bereavement itself, they are not signs that a person is prone to depression generally.

Evaluation of Mojtabai (2011)

Strengths

• The use of a longitudinal design meant that the researchers were able to track depressive episodes across time which enabled them to form their conclusion that depression is a natural consequence of bereavement, thus the findings have validity
• Research such as this is important as it can help to inform future revisions and reviews of the DSM-5 which shows that the findings have good application

Weaknesses

• It is possible that participants suffering from depression may not be able to assess their feelings and mood objectively which means that the results could lack reliability
• The responses of the participants may have been affected by investigator effects (i.e. they may have  liked/disliked the researcher disproportionately) which would in turn decrease the validity of their response