There are a few different potential relationships between social phobia and depression. In many instances, one will exacerbate the other. For instance, an individual suffering from depression may begin to feel worried or nervous about being in social situations. On the other hand, an individual who first suffers from social phobia may begin to experience depression as a result of a loss of personal relationships, or even the ability to leave the house, in severe cases. An individual who is then suffering from both social phobia and depression might then be more prone to panic attacks or severe anxiety.
In most cases, the relationship between social phobia and depression begins first with a bit of social anxiety, often in childhood. This anxiety may progress to a full-blown social phobia or social anxiety disorder (SAD), in which people have an intense fear of things such as being up in front of a crowd, or simply being in a group of people for fear that something embarrassing will happen. This may occur as just a general, unrealized fear, or it may occur as a result of an embarrassing situation that makes people want to avoid similar situations in the future.
Once a social phobia like this has taken hold, people may begin withdrawing from social situations, which may make work or relationships difficult. They may also experience a general feeling of anxiety about their lives and their future. Often, this will then progress to depression, which will make it even more difficult to find the motivation to leave the house or participate in social events.
In other, less common cases, depression may occur first, and then lead to social phobia. People suffering from depression may find it difficult to think quickly and participate in conversations, or may find it difficult to leave their houses or participate in activities they used to enjoy. Knowing this, they may then begin to develop a fear of social situations. It is rare for this to progress to a full social phobia, though it is certainly possible.
Finally, when social phobia and depression are combined, they sometimes lead to other issues such as panic attacks or a generalized sense of anxiety. This can worsen the other conditions as well. As a result, it is important to receive treatment as soon as possible for social phobia and depression to ensure that they do not negatively impact an individual's life.