Validity and Reliability of Diagnosis of Depression Research

1) Pontizovsky 2006 - Short term
D> Looked at agreement on diagnosis of type of depression on admission and a year later on release in Islamic psychiatric hospitals in 2003. 

F> There was an 83 PPV rate (83% stayed them same.) Therefore 2/10 diagnoses changed.

S>   Low reliability in short term diagnosis

E>  -Problem could have actually changed
-High ecological validity- natural observation.

2) Baca-Garcia 2007 - Long term
D> Looked at 2322 patients assessed at a spanish psychiatric hospital between 1992-2004. Each patient was assessed atleast 10 times. 

F> 54 PPV (54% stayed the same)

S> Even lower rates of reliability over long term assessments. 

E> Large sample size and meta-analysis, so generalisable. 

Sanchez-Villegas 2008
D> Gave the diagnostic criteria for depression from the DSM-IV to 62 people who had already been diagnosed as depression and to 42 people without a diagnosis.

F> 74% with a diagnosis were correctly identified as depressed
     81% without a diagnosis were confirmed as not depressed

S> Low validity of diagnosis of depression
     Doctors often get it wrong

E> -Situation may have actually changed
     -Small sample size  

Cinnerella and Loewenthal 1999

D> Interviewed a range of people of different cultures living in Britain in their own home, about depression and schizophrenia

F> All cultures agreed that depression was a result of life events and environmental conditions
-All cultures except Catholics had a fear of being misunderstood by a medical professional 
-Black Christians and Muslim groups both felt that these conditions were shameful

S> Valid and reliable diagnoses can be difficult as many groups are unwilling to share  

Levav et al 1997

D> Compared the frequency of alcholism and depression in American Jews, Catholics and Protestants.

F> -Much higher rate of depression and lower rate of alcholism in Jews
     -Jewish Men are twice as likely to be diagnosed as women

S> Some aspect of Jewish culture makes the men find it easier to deal with times of adversity with depression rather than alcoholism.  

Could be a genetic predisposition but most likely to be social influences of the culture.

Littlewood and Lipsedge 1997- Case Study

D> Reviewed the assessment given of 'Calvin', a Jamaican man who got arrested under suspicion of stealing. 

F> Instances of institutional racism.
-Said he had a straggly goatee- Doesn't shave for religion.
-Called him arrogant- Had just been arrested.

S> How bias in the system can affect diagnosis given. 

Lamy 1996 STIGMA
Found that mothers would prefer to leave their children with a person who had been convicted of a crime and sent to jail than somebody labelled as a mental patient.

Farina et al 1971
D> Studied patients who had formerly been treated for depression by setting them up for an interview with prospective employers.
     Split into 2 groups:
1) The employer knew they had a history of depression and participants knew this
2) The employer knew they were previously medical patients and participants knew they didn't know about their depression
-They then had to complete the interview and rate their feelings 

F>    -When the interviewer knew of their depression they felt unappreciated and performed         worse on the tasks
        -When the interviewer knew of their past they were rated as tense and anxious.

S>  Self- fulfilling prophecy and stigma of psychiatrists affect behaviour.