Well, I didn't watch the film, but I actually covered the topic as my thesis when working on my popular culture degree (yes, that's a thing, stick it! lol)
To sum up approximately 10+ pages of heavy study and jargon, I included that, while the gothic culture, was not necessarily correlated, the ability for those who are depressed, bipolar, or have other forms of mental illness can relate to the common imagery, the feeling of separation from mainstream society, and the attempt to find beauty in darkness and things not normally found beautiful as a way to deal with their own inner demons and illnesses.