Duplication Error

I am getting this error: Illuminate\Database\QueryException : SQLSTATE[42S21]: Column already exists: 1060 Duplicate column name 'chatter_category_id' (SQL: alter table chatter_discussion add chatter_category_id int unsigned not null, add user_id bigint unsigned not null)

My Migration file is this
			
			Schema::table('chatter_discussion', function (Blueprint $table) {
        $table->integer('chatter_category_id')->unsigned()->index();
        $table->foreign('chatter_category_id')->references('id')->on('chatter_categories')
                    ->onDelete('cascade')
                    ->onUpdate('cascade');
        $table->bigInteger('user_id')->unsigned()->index();
        $table->foreign('user_id')->references('id')->on('users')
                    ->onDelete('cascade')
                    ->onUpdate('cascade');
    });
    Schema::table('chatter_post', function (Blueprint $table) {
        $table->integer('chatter_discussion_id')->unsigned()->index();
        $table->foreign('chatter_discussion_id')->references('id')->on('chatter_discussion')
                    ->onDelete('cascade')
                    ->onUpdate('cascade');
        $table->bigInteger('user_id')->unsigned()->index();
        $table->foreign('user_id')->references('id')->on('users')
                    ->onDelete('cascade')
                    ->onUpdate('cascade');
    });