[3] He made his league debut on 16 October 2004, as a second-half substitute for David Worrell in a 2–1 home defeat by Wigan Athletic.
In August 2006, he trained with Scottish Premier League club Motherwell with a view to a loan move, but the deal eventually fell through.
[7] He played his final league game for the club in his next match against Southampton, coming on in the 80th minute in a 1–1 draw on New Year's Day 2007.
[14] During his 10 loan matches with the Bees,[15] Dickson impressed Brentford manager Andy Scott enough that he was offered a long-term contract by the club in January 2008.
[20] On 10 June 2010 it was reported that Dickson had signed a deal to join the Bees' league rivals Southampton, with the transfer fee set to be agreed at a tribunal.
[25] With the Saints playing Championship football in 2011–12, Dickson found himself limited to League Cup appearances in the early stages of the season.
[29] Following the expiry of his Yeovil spell, Dickson signed on emergency loan for Leyton Orient on 9 February 2012, joining up with the O's until the end of the season.
[31] During his nine games with the club, Dickson was sent off twice, once for a second bookable offence in a 1–0 win against Oldham Athletic on 27 March and the second a straight red card on 14 April against Sheffield United.
[2][3] With his club now plying their trade in the Premier League, Dickson found himself further out of favour, as he was eventually loaned out to Bradford City on 11 January until the end of the season.
[38] After a sprightly start to his Colchester career, Dickson was knocked back by a debilitating illness in September 2013, leaving him out of action for two months, as he was replaced by Everton loanee Luke Garbutt.