Hadden, who named a 35-man squad which will begin training next week, told www.scottishrugby.org that White's position was never in doubt.
He said: "Jason is a key figure for us. He sets the tone as a leader both on and off the field and I look forward to working with him again during this season's championship."
The Scotland coach was keen to highlight the strength in depth available to him this year.
Twenty-two of the squad are home based, among them six uncapped players - Edinburgh backs Ben Cairns, Nick De Luca and Calum MacRae, Glasgow wing Thom Evans and prop Moray Low and Edinburgh back-row forward Ross Rennie.
Cairns, 22, a product of the Scotland age group set-up and Scotland Sevens, is listed in the senior Scotland squad for the first time, while wing Simon Danielli returns after missing the World Cup through injury.
Hadden said: "I continue to be impressed with the competition for places in the squad.
"A number of players have maintained their good form from the World Cup but they are going to be pushed extremely hard by some of our young, up-and-coming talent in the next few weeks."
Omitted from the squad since the World Cup are lock Scott Murray, prop Craig Smith and hooker Scott Lawson.
Hadden insists there will be opportunities for that trio, and other contenders outside the training squad, to push for places.
However, one player who has ruled himself out is centre Marcus Di Rollo.
His omission follows his own commitment to make himself available exclusively for his French club, Toulouse, during this season's championship, but he vowed to compete for his Scotland place again in the future.
Di Rollo said: "Making myself unavailable for Scotland for this year's 6 Nations Championship was not a decision I took lightly.
"After a period of injury and transition from Scotland to France I felt it would be beneficial for my game to take some time to settle into my new club."
Scotland squad for training at Murrayfield on Monday 14 January in preparation for the 2008 RBS 6 Nations Championships
Backs: M Blair, B Cairns (both Edinburgh), C Cusiter (Perpignan), S Danielli (Ulster), N De Luca (Edinburgh), T Evans (Glasgow Warriors), P Godman (Edinburgh), R Lamont (Sale Sharks), R Lawson (Gloucester), C MacRae (Edinburgh), G Morrison, D Parks (both Glasgow Warriors), C Paterson (Gloucester), H Southwell (Edinburgh), N Walker (Ospreys), S Webster (Edinburgh).
Forwards: J Barclay, J Beattie, K Brown (all Glasgow Warriors), D Callam (Edinburgh), A Dickinson (Gloucester), R Ford (Edinburgh), J Hamilton (Leicester Tigers), N Hines (Perpignan), A Hogg, A Jacobsen (both Edinburgh), A Kellock (Glasgow Warriors), G Kerr (Edinburgh), M Low (Glasgow Warriors), S MacLeod (Llanelli Scarlets), Euan Murray (Northampton), R Rennie (Edinburgh), A Strokosch (Gloucester), F Thomson (Glasgow Warriors), J White (Sale, capt).
Injured but invited to the training session: Andrew Henderson (Glasgow Warriors) - knee injury; Simon Taylor (Stade Francais) - thumb injury; and Rob Dewey (Ulster) - knee injury.