Well, I still don’t really understand exactly what your question is, so I am going to break it down into segments… (I apologise if I have not properly answered it.) Sorry about my vagueness. (Also, this isn’t really taught in VCE psychology; your question is very much intertwined with philosophy.)
a) The use of differential diagnosis and the problems associated with it. In medicine (generally) diagnosis is aided by the use of technologies such as scans and blood tests. However in psychiatry, obviously one of the only methods used in determining the problem the person has would be a list of their symptoms. I think various problems arise from the use of this method. Firstly, you can’t be certain you have the correct diagnosis and the aetiology of the symptoms isn’t actually physiological as opposed to somatic or psychological (psychiatry is an underdeveloped field; I believe a majority of mental illness is actually physiological.) There also could be diseases and conditions that haven’t been discovered yet etc. So, the answer to the question (which was in your first post):
‘How do you know you’ve got the right diagnosis, when there could potentially be fifty connections?’
Well, quite simply, you don’t. It’s all a matter of trial and error. Doctors nominate the most likely diagnosis, attempt to treat it and then go from there. (Note: Sometimes, some illnesses can have unique characteristics, and thus easier to identify)
b) What is normal? Going back to the VCE/ IB psychology course, psychologists have a framework for defining what is abnormal/ normal behaviour. It’s called, ‘the 6 approaches to normality’. (This is just to give you an idea of how we’re taught psychologists define it.)
The approaches: The Sociocultural approach: The Sociocultural approach basically defines abnormality as a failure to conform with social norms, or if you behave in a manner which is not socially acceptable etc.
Limitations of this approach: Obviously definitions of ‘normal’ and ‘abnormal’ behaviour vary from culture to culture and country to country etc.
The functional approach: Refers to how someone functions in society, and how an individual can perform tasks such as attending school, getting out of bed or eating sufficiently. So, under this approach, someone who cannot take care of him or herself adequately would be defined as abnormal.
Limitations: Doesn’t necessarily take their situation into account. For example, someone may be unable to attend school or get out of bed due to illness.
Historical approach: This approach essentially takes the era in which the behaviour occurred into account. So, if you participated in an activity in 1965 that was considered normal in 1965 but abnormal in 2008, it would be considered ‘normal’. I think. Yeah.
The situational approach: The situational approach considers the situation or environment in which the behaviour was carried out. (If that makes sense.) For example, some people may consider excessive crying abnormal, however not if it was at a funeral or after a loved one had passed away.
Another example: laughing could be classified as normal. But not at a funeral.
Painting the exterior of your house might be considered a pretty normal behaviour. But it wouldn’t be if it were pouring with rain when you were doing it.
Limitations: doesn’t take culture into account and such.
The medical approach: Basically, it considers all abnormal behaviour to have a physical/biological aetiology. Someone behaving in a NORMAL fashion just symbolises the absence of certain physical impairments.
Limitations: is reductionist. Mental illness may be caused by environmental and biological factors etc.
The statistical approach:
The ‘statistical approach’ uses statistics to determine the most common characteristics and behaviours occurring within society. Behaviour which are common statistically are considered normal.
Disadvantages of the approach: The most commonly occurring characteristics are not necessarily normal. For example, a large proportion of teenagers binge drink. Does that make it normal?
So, as you can see, there are also various problems associated with classifying abnormal/ normal behaviour. Psychology is a grey area. There's a lot we don't know. But, basically behaviour which is considered abnormal under all or one of the approaches above would be considered 'abnormal'.
c) self-help websites It depends what sort of self-help websites.
Here's a website which has a large list of psychology websites which you can visit and find information:
http://psychlib.princeton.edu/links.htm d) "Because sometimes I've truthfully answered yes to something when someone else being asked the same thing about me will truthfully answer no"That's all a matter of individual perception; it varies from person to person. In one person's eyes you may be one thing, however in another's you may be something different. So you never do know... lol.
Sorry, that probably didn't answer your questions lol.